diff --git a/client/src/components/Planner/DayPlanSidebar.tsx b/client/src/components/Planner/DayPlanSidebar.tsx
index 3b7a5a22..14fcd498 100644
--- a/client/src/components/Planner/DayPlanSidebar.tsx
+++ b/client/src/components/Planner/DayPlanSidebar.tsx
@@ -2,7 +2,7 @@
 interface DragDataPayload { placeId?: string; assignmentId?: string; noteId?: string; reservationId?: string; fromDayId?: string; phase?: 'single' | 'start' | 'middle' | 'end' }
 declare global { interface Window { __dragData: DragDataPayload | null } }
 
-import React, { useState, useEffect, useRef, useMemo } from 'react'
+import React, { useState, useEffect, useLayoutEffect, useRef, useMemo } from 'react'
 import ReactDOM from 'react-dom'
 import { ChevronDown, ChevronRight, ChevronUp, ChevronsDownUp, ChevronsUpDown, Navigation, RotateCcw, ExternalLink, Clock, Pencil, GripVertical, Ticket, Plus, FileText, Check, Trash2, Info, MapPin, Star, Heart, Camera, Lightbulb, Flag, Bookmark, Train, Bus, Plane, Car, Ship, Coffee, ShoppingBag, AlertTriangle, FileDown, Lock, Hotel, Utensils, Users, Undo2, X, Route as RouteIcon } from 'lucide-react'
 
@@ -191,6 +191,8 @@ interface DayPlanSidebarProps {
   onEditTransport?: (reservation: Reservation) => void
   onEditReservation?: (reservation: Reservation) => void
   onAddBookingToAssignment?: (dayId: number, assignmentId: number) => void
+  initialScrollTop?: number
+  onScrollTopChange?: (top: number) => void
 }
 
 const DayPlanSidebar = React.memo(function DayPlanSidebar({
@@ -219,6 +221,8 @@ const DayPlanSidebar = React.memo(function DayPlanSidebar({
   onEditTransport,
   onEditReservation,
   onAddBookingToAssignment,
+  initialScrollTop,
+  onScrollTopChange,
 }: DayPlanSidebarProps) {
   const toast = useToast()
   const { t, language, locale } = useTranslation()
@@ -271,6 +275,12 @@ const DayPlanSidebar = React.memo(function DayPlanSidebar({
   } | null>(null)
   const inputRef = useRef(null)
   const dragDataRef = useRef(null)
+  const scrollContainerRef = useRef<HTMLDivElement | null>(null)
+  useLayoutEffect(() => {
+    if (scrollContainerRef.current && initialScrollTop) {
+      scrollContainerRef.current.scrollTop = initialScrollTop
+    }
+  }, [])
   const initedTransportIds = useRef(new Set<number>()) // Speichert Drag-Daten als Backup (dataTransfer geht bei Re-Render verloren)
   // Remember which assignment we last auto-scrolled into view so we don't
   // keep yanking the user back whenever they scroll away while the same
@@ -1118,7 +1128,7 @@ const DayPlanSidebar = React.memo(function DayPlanSidebar({
       </div>
 
       {/* Tagesliste */}
-      <div className={`scroll-container${draggingId ? '' : ' trek-stagger'}`} style={{ flex: 1, overflowY: 'auto', minHeight: 0 }}>
+      <div className={`scroll-container${draggingId ? '' : ' trek-stagger'}`} style={{ flex: 1, overflowY: 'auto', minHeight: 0 }} ref={scrollContainerRef} onScroll={(e) => onScrollTopChange?.((e.currentTarget as HTMLElement).scrollTop)}>
         {days.map((day, index) => {
           const isSelected = selectedDayId === day.id
           const isExpanded = expandedDays.has(day.id)
diff --git a/client/src/components/Planner/PlacesSidebar.tsx b/client/src/components/Planner/PlacesSidebar.tsx
index a3d45d63..50303768 100644
--- a/client/src/components/Planner/PlacesSidebar.tsx
+++ b/client/src/components/Planner/PlacesSidebar.tsx
@@ -1,6 +1,6 @@
 import React from 'react'
 import ReactDOM from 'react-dom'
-import { useState, useMemo, useEffect, useRef, useCallback } from 'react'
+import { useState, useMemo, useEffect, useLayoutEffect, useRef, useCallback } from 'react'
 import { Search, Plus, X, CalendarDays, Pencil, Trash2, ExternalLink, Navigation, Upload, ChevronDown, Check, MapPin, Eye, Route } from 'lucide-react'
 import PlaceAvatar from '../shared/PlaceAvatar'
 import { getCategoryIcon } from '../shared/categoryIcons'
@@ -34,6 +34,8 @@ interface PlacesSidebarProps {
   onCategoryFilterChange?: (categoryIds: Set<string>) => void
   onPlacesFilterChange?: (filter: string) => void
   pushUndo?: (label: string, undoFn: () => Promise<void> | void) => void
+  initialScrollTop?: number
+  onScrollTopChange?: (top: number) => void
 }
 
 interface MemoPlaceRowProps {
@@ -145,6 +147,7 @@ const MemoPlaceRow = React.memo(function MemoPlaceRow({
 const PlacesSidebar = React.memo(function PlacesSidebar({
   tripId, places, categories, assignments, selectedDayId, selectedPlaceId,
   onPlaceClick, onAddPlace, onAssignToDay, onEditPlace, onDeletePlace, onBulkDeletePlaces, onBulkDeleteConfirm, days, isMobile, onCategoryFilterChange, onPlacesFilterChange, pushUndo,
+  initialScrollTop, onScrollTopChange,
 }: PlacesSidebarProps) {
   const { t } = useTranslation()
   const toast = useToast()
@@ -159,6 +162,12 @@ const PlacesSidebar = React.memo(function PlacesSidebar({
   const [sidebarDropFile, setSidebarDropFile] = useState<File | null>(null)
   const [sidebarDragOver, setSidebarDragOver] = useState(false)
   const sidebarDragCounter = useRef(0)
+  const scrollContainerRef = useRef<HTMLDivElement | null>(null)
+  useLayoutEffect(() => {
+    if (scrollContainerRef.current && initialScrollTop) {
+      scrollContainerRef.current.scrollTop = initialScrollTop
+    }
+  }, [])
 
   const handleSidebarDragEnter = (e: React.DragEvent) => {
     if (!canEditPlaces) return
@@ -636,7 +645,7 @@ const PlacesSidebar = React.memo(function PlacesSidebar({
       )}
 
       {/* Liste */}
-      <div className="trek-stagger" style={{ flex: 1, overflowY: 'auto', minHeight: 0 }}>
+      <div className="trek-stagger" style={{ flex: 1, overflowY: 'auto', minHeight: 0 }} ref={scrollContainerRef} onScroll={(e) => onScrollTopChange?.((e.currentTarget as HTMLElement).scrollTop)}>
         {filtered.length === 0 ? (
           <div style={{ display: 'flex', flexDirection: 'column', alignItems: 'center', padding: '40px 16px', gap: 8 }}>
             <span style={{ fontSize: 13, color: 'var(--text-faint)' }}>
diff --git a/client/src/pages/TripPlannerPage.test.tsx b/client/src/pages/TripPlannerPage.test.tsx
index 78096249..3ea43503 100644
--- a/client/src/pages/TripPlannerPage.test.tsx
+++ b/client/src/pages/TripPlannerPage.test.tsx
@@ -1474,6 +1474,56 @@ describe('TripPlannerPage', () => {
     });
   });
 
+  describe('FE-PAGE-PLANNER-051: Mobile Plan sidebar stays mounted after onPlaceClick (issue #932)', () => {
+    it('does not unmount the mobile Plan portal when a place is tapped, preserving scroll position', async () => {
+      vi.useFakeTimers();
+      Object.defineProperty(window, 'innerWidth', { writable: true, configurable: true, value: 375 });
+
+      const place = buildPlace({ id: 1, trip_id: 42, lat: 48.8566, lng: 2.3522 });
+      const assignment = buildAssignment({ id: 10, day_id: 99, place, order_index: 0 });
+      seedTripStore({ id: 42 });
+      seedStore(useTripStore, {
+        places: [place],
+        assignments: { '99': [assignment] },
+      } as any);
+
+      renderPlannerPage(42);
+      act(() => { vi.runAllTimers(); });
+      vi.useRealTimers();
+
+      await waitFor(() => {
+        expect(screen.getByTestId('day-plan-sidebar')).toBeInTheDocument();
+      });
+
+      // Open the mobile Plan portal via the bottom-nav Plan button (selector mirrors FE-PAGE-PLANNER-049).
+      const mobilePlanBtn = Array.from(document.body.querySelectorAll('button')).find(
+        b => b.textContent === 'Plan' && !b.getAttribute('title'),
+      );
+      expect(mobilePlanBtn).toBeTruthy();
+      await act(async () => { fireEvent.click(mobilePlanBtn!); });
+
+      await waitFor(() => {
+        expect(screen.getAllByTestId('day-plan-sidebar').length).toBe(2);
+      });
+
+      // The mock factory overwrites capturedDayPlanSidebarProps on each mount,
+      // so current holds the mobile portal instance's props.
+      const mobileOnPlaceClick = capturedDayPlanSidebarProps.current.onPlaceClick;
+      expect(typeof mobileOnPlaceClick).toBe('function');
+
+      await act(async () => {
+        mobileOnPlaceClick(place.id, assignment.id);
+      });
+
+      // Invariant: portal must NOT unmount — both instances persist.
+      // Pre-fix: collapses to 1 (setMobileSidebarOpen(null) destroyed scroll container).
+      // Post-fix: stays at 2, browser preserves scrollTop on the living DOM node.
+      expect(screen.getAllByTestId('day-plan-sidebar').length).toBe(2);
+
+      Object.defineProperty(window, 'innerWidth', { writable: true, configurable: true, value: 1024 });
+    });
+  });
+
   describe('FE-PAGE-PLANNER-037: onExpandedDaysChange covers mapPlaces hidden logic', () => {
     it('calls onExpandedDaysChange to trigger mapPlaces hidden set computation', async () => {
       vi.useFakeTimers();
diff --git a/client/src/pages/TripPlannerPage.tsx b/client/src/pages/TripPlannerPage.tsx
index 54cc4726..8be7cd58 100644
--- a/client/src/pages/TripPlannerPage.tsx
+++ b/client/src/pages/TripPlannerPage.tsx
@@ -272,6 +272,8 @@ export default function TripPlannerPage(): React.ReactElement | null {
   const [fitKey, setFitKey] = useState<number>(0)
   const initialFitTripId = useRef<number | null>(null)
   const [mobileSidebarOpen, setMobileSidebarOpen] = useState<'left' | 'right' | null>(null)
+  const mobilePlanScrollTopRef = useRef<number>(0)
+  const mobilePlacesScrollTopRef = useRef<number>(0)
   const [deletePlaceId, setDeletePlaceId] = useState<number | null>(null)
   const [deletePlaceIds, setDeletePlaceIds] = useState<number[] | null>(null)
 
@@ -1114,8 +1116,8 @@ export default function TripPlannerPage(): React.ReactElement | null {
                   </div>
                   <div style={{ flex: 1, overflow: 'auto' }}>
                     {mobileSidebarOpen === 'left'
-                      ? <DayPlanSidebar tripId={tripId} trip={trip} days={days} places={places} categories={categories} assignments={assignments} selectedDayId={selectedDayId} selectedPlaceId={selectedPlaceId} selectedAssignmentId={selectedAssignmentId} onSelectDay={(id) => { handleSelectDay(id); setMobileSidebarOpen(null) }} onPlaceClick={(placeId, assignmentId) => { handlePlaceClick(placeId, assignmentId); setMobileSidebarOpen(null) }} onReorder={handleReorder} onUpdateDayTitle={handleUpdateDayTitle} onAssignToDay={handleAssignToDay} onRouteCalculated={(r) => { if (r) { setRoute(r.coordinates); setRouteInfo({ distance: r.distanceText, duration: r.durationText }) } }} reservations={reservations} visibleConnectionIds={visibleConnections} onToggleConnection={toggleConnection} onAddReservation={(dayId) => { setEditingReservation(null); tripActions.setSelectedDay(dayId); setShowReservationModal(true); setMobileSidebarOpen(null) }} onAddPlace={() => { setEditingPlace(null); setShowPlaceForm(true); setMobileSidebarOpen(null) }} onDayDetail={(day) => { setShowDayDetail(day); setSelectedPlaceId(null); selectAssignment(null); setMobileSidebarOpen(null) }} accommodations={tripAccommodations} onNavigateToFiles={() => { setMobileSidebarOpen(null); handleTabChange('dateien') }} onExpandedDaysChange={setExpandedDayIds} pushUndo={pushUndo} canUndo={canUndo} lastActionLabel={lastActionLabel} onUndo={handleUndo} onEditTransport={can('day_edit', trip) ? (reservation) => { setEditingTransport(reservation); setTransportModalDayId(reservation.day_id ?? null); setShowTransportModal(true); setMobileSidebarOpen(null) } : undefined} onEditReservation={can('reservation_edit', trip) ? (r) => { setEditingReservation(r); setShowReservationModal(true); setMobileSidebarOpen(null) } : undefined} />
-                      : <PlacesSidebar tripId={tripId} places={places} categories={categories} assignments={assignments} selectedDayId={selectedDayId} selectedPlaceId={selectedPlaceId} onPlaceClick={(placeId) => { handlePlaceClick(placeId); setMobileSidebarOpen(null) }} onAddPlace={() => { setEditingPlace(null); setShowPlaceForm(true); setMobileSidebarOpen(null) }} onAssignToDay={handleAssignToDay} onEditPlace={(place) => { setEditingPlace(place); setEditingAssignmentId(null); setShowPlaceForm(true); setMobileSidebarOpen(null) }} onDeletePlace={(placeId) => handleDeletePlace(placeId)} onBulkDeletePlaces={(ids) => setDeletePlaceIds(ids)} onBulkDeleteConfirm={(ids) => confirmDeletePlaces(ids)} days={days} isMobile onCategoryFilterChange={setMapCategoryFilter} onPlacesFilterChange={setMapPlacesFilter} pushUndo={pushUndo} />
+                      ? <DayPlanSidebar tripId={tripId} trip={trip} days={days} places={places} categories={categories} assignments={assignments} selectedDayId={selectedDayId} selectedPlaceId={selectedPlaceId} selectedAssignmentId={selectedAssignmentId} onSelectDay={(id) => { handleSelectDay(id); setMobileSidebarOpen(null) }} onPlaceClick={(placeId, assignmentId) => { handlePlaceClick(placeId, assignmentId) }} onReorder={handleReorder} onUpdateDayTitle={handleUpdateDayTitle} onAssignToDay={handleAssignToDay} onRouteCalculated={(r) => { if (r) { setRoute(r.coordinates); setRouteInfo({ distance: r.distanceText, duration: r.durationText }) } }} reservations={reservations} visibleConnectionIds={visibleConnections} onToggleConnection={toggleConnection} onAddReservation={(dayId) => { setEditingReservation(null); tripActions.setSelectedDay(dayId); setShowReservationModal(true); setMobileSidebarOpen(null) }} onAddPlace={() => { setEditingPlace(null); setShowPlaceForm(true); setMobileSidebarOpen(null) }} onDayDetail={(day) => { setShowDayDetail(day); setSelectedPlaceId(null); selectAssignment(null); setMobileSidebarOpen(null) }} accommodations={tripAccommodations} onNavigateToFiles={() => { setMobileSidebarOpen(null); handleTabChange('dateien') }} onExpandedDaysChange={setExpandedDayIds} pushUndo={pushUndo} canUndo={canUndo} lastActionLabel={lastActionLabel} onUndo={handleUndo} onEditTransport={can('day_edit', trip) ? (reservation) => { setEditingTransport(reservation); setTransportModalDayId(reservation.day_id ?? null); setShowTransportModal(true); setMobileSidebarOpen(null) } : undefined} onEditReservation={can('reservation_edit', trip) ? (r) => { setEditingReservation(r); setShowReservationModal(true); setMobileSidebarOpen(null) } : undefined} initialScrollTop={mobilePlanScrollTopRef.current} onScrollTopChange={(top) => { mobilePlanScrollTopRef.current = top }} />
+                      : <PlacesSidebar tripId={tripId} places={places} categories={categories} assignments={assignments} selectedDayId={selectedDayId} selectedPlaceId={selectedPlaceId} onPlaceClick={(placeId) => { handlePlaceClick(placeId); setMobileSidebarOpen(null) }} onAddPlace={() => { setEditingPlace(null); setShowPlaceForm(true); setMobileSidebarOpen(null) }} onAssignToDay={handleAssignToDay} onEditPlace={(place) => { setEditingPlace(place); setEditingAssignmentId(null); setShowPlaceForm(true); setMobileSidebarOpen(null) }} onDeletePlace={(placeId) => handleDeletePlace(placeId)} onBulkDeletePlaces={(ids) => setDeletePlaceIds(ids)} onBulkDeleteConfirm={(ids) => confirmDeletePlaces(ids)} days={days} isMobile onCategoryFilterChange={setMapCategoryFilter} onPlacesFilterChange={setMapPlacesFilter} pushUndo={pushUndo} initialScrollTop={mobilePlacesScrollTopRef.current} onScrollTopChange={(top) => { mobilePlacesScrollTopRef.current = top }} />
                     }
                   </div>
                 </div>