diff --git a/client/src/components/Planner/PlaceFormModal.tsx b/client/src/components/Planner/PlaceFormModal.tsx
index c2eb7086e..6e3878487 100644
--- a/client/src/components/Planner/PlaceFormModal.tsx
+++ b/client/src/components/Planner/PlaceFormModal.tsx
@@ -1196,9 +1196,8 @@ export default function PlaceFormModal(props: PlaceFormModalProps) {
                 options={[
                   { value: '', label: t('places.noCategory') },
                   ...(categories || []).map(c => ({
-                    // form.category_id is a string; CustomSelect matches options by
-                    // strict equality, so the option value must be a string too —
-                    // otherwise the chosen category never renders in the trigger.
+                    // A string like form.category_id, so the picked option hands
+                    // back the same kind of value the form already keeps.
                     value: String(c.id),
                     label: c.name,
                   })),
diff --git a/client/src/components/Trips/TripMembersModal.test.tsx b/client/src/components/Trips/TripMembersModal.test.tsx
index d0dfb2e97..d82fa8396 100644
--- a/client/src/components/Trips/TripMembersModal.test.tsx
+++ b/client/src/components/Trips/TripMembersModal.test.tsx
@@ -1,4 +1,4 @@
-// FE-COMP-MEMBERS-001 to FE-COMP-MEMBERS-056
+// FE-COMP-MEMBERS-001 to FE-COMP-MEMBERS-057
 import type { Mock } from 'vitest';
 import { act, render, screen, fireEvent, waitFor } from '../../../tests/helpers/render';
 import userEvent from '@testing-library/user-event';
@@ -725,6 +725,26 @@ describe('TripMembersModal', () => {
     expect(addToast).toHaveBeenCalledWith('alice added', 'success', undefined);
   });
 
+  // #2478: the pick showed nowhere, only the Invite button knew about it.
+  it('FE-COMP-MEMBERS-057: the picked user shows in the field before the invite is sent', async () => {
+    const user = userEvent.setup();
+    server.use(http.post('/api/trips/1/members', () => HttpResponse.json({ success: true })));
+    render(<TripMembersModal {...defaultProps} />);
+
+    await screen.findByText('Invite User');
+    const trigger = screen.getByText('Select user…').closest('button') as HTMLButtonElement;
+    await user.click(trigger);
+    await user.click(await screen.findByRole('button', { name: 'alice' }));
+
+    expect(trigger).toHaveTextContent('alice');
+    expect(screen.queryByText('Select user…')).toBeNull();
+    expect(screen.getByRole('button', { name: 'Invite' })).toBeEnabled();
+
+    // Once sent, the field is free for the next pick again.
+    await user.click(screen.getByRole('button', { name: 'Invite' }));
+    await waitFor(() => expect(trigger).toHaveTextContent('Select user…'));
+  });
+
   it('FE-COMP-MEMBERS-042: transferring ownership reloads the app', async () => {
     const onClose = vi.fn();
     const reload = vi.fn();
diff --git a/client/src/components/shared/CustomSelect.test.tsx b/client/src/components/shared/CustomSelect.test.tsx
index 2f13fc5b6..da081bbc7 100644
--- a/client/src/components/shared/CustomSelect.test.tsx
+++ b/client/src/components/shared/CustomSelect.test.tsx
@@ -1,4 +1,4 @@
-import { render, screen, fireEvent } from '../../../tests/helpers/render';
+import { render, screen, within } from '../../../tests/helpers/render';
 import userEvent from '@testing-library/user-event';
 import CustomSelect from './CustomSelect';
 
@@ -145,6 +145,46 @@ describe('CustomSelect', () => {
     expect(menu.style.maxWidth).toBe('180px');
   });
 
+  // #2478: the trip share dialog stored String(value) against options keyed by numeric
+  // user ids, so the pick never showed in the trigger although it was made.
+  const USERS = [
+    { value: 7, label: 'alice' },
+    { value: 12, label: 'bob' },
+  ];
+
+  it('FE-COMP-SELECT-014: a value held as text finds the option keyed by the same number', async () => {
+    const user = userEvent.setup();
+    render(<CustomSelect value="12" onChange={onChange} options={USERS} placeholder="Pick a user" />);
+
+    const trigger = screen.getByRole('button');
+    expect(trigger).toHaveTextContent('bob');
+    expect(screen.queryByText('Pick a user')).toBeNull();
+
+    // The open list marks the same option with its check, and only that one.
+    await user.click(trigger);
+    const menu = within(screen.getByText('alice').closest('div[style*="position: fixed"]') as HTMLElement);
+    expect(menu.getByRole('button', { name: 'bob' }).querySelector('svg')).not.toBeNull();
+    expect(menu.getByRole('button', { name: 'alice' }).querySelector('svg')).toBeNull();
+  });
+
+  it('FE-COMP-SELECT-015: a numeric value finds the option keyed by the same text', () => {
+    render(<CustomSelect value={3} onChange={onChange} options={[{ value: '3', label: 'March' }, { value: '4', label: 'April' }]} placeholder="Month" />);
+    expect(screen.getByRole('button')).toHaveTextContent('March');
+  });
+
+  it('FE-COMP-SELECT-016: a caller holding nothing still sees the placeholder', () => {
+    render(<CustomSelect value={null} onChange={onChange} options={[{ value: '', label: 'Nobody' }, ...USERS]} placeholder="Pick a user" />);
+    expect(screen.getByRole('button')).toHaveTextContent('Pick a user');
+  });
+
+  it('FE-COMP-SELECT-017: picking hands back the option value as it is', async () => {
+    const user = userEvent.setup();
+    render(<CustomSelect value="" onChange={onChange} options={USERS} />);
+    await user.click(screen.getByRole('button'));
+    await user.click(screen.getByRole('button', { name: 'alice' }));
+    expect(onChange).toHaveBeenCalledWith(7);
+  });
+
   it('FE-COMP-SELECT-008: disabled state prevents the dropdown from opening', async () => {
     const user = userEvent.setup();
     render(<CustomSelect value="" onChange={onChange} options={OPTIONS} disabled={true} placeholder="Pick" />);
diff --git a/client/src/components/shared/CustomSelect.tsx b/client/src/components/shared/CustomSelect.tsx
index 6c02c27d1..82932e8b3 100644
--- a/client/src/components/shared/CustomSelect.tsx
+++ b/client/src/components/shared/CustomSelect.tsx
@@ -4,8 +4,8 @@ import { ChevronDown, Check } from 'lucide-react'
 import { useAnchoredPosition, scrollAnchorIntoView } from '../../hooks/useAnchoredPosition'
 
 interface SelectOption {
-  // Callers use both string keys and numeric ids (e.g. day/place ids) as values;
-  // the component only does strict-equality lookups and key rendering, so either works.
+  // Callers use both string keys and numeric ids (e.g. day/place ids) as values, and
+  // the value they hold need not be of the same kind as the options: see sameValue.
   value: string | number
   label: string
   icon?: React.ReactNode
@@ -36,6 +36,20 @@ interface CustomSelectProps {
   menuFit?: 'anchor' | 'content'
 }
 
+/**
+ * Whether an option is the one the caller holds.
+ *
+ * onChange hands back the option's own value, and callers routinely store it in another
+ * form: the trip share dialog kept String(value) against options keyed by numeric user
+ * ids, so a strict comparison never found the pick and the trigger stayed on its
+ * placeholder while the invite button already knew who was chosen (#2478). An id reads
+ * the same as a number or as text, so both sides are compared as text. A caller holding
+ * nothing (null or undefined at runtime) matches no option.
+ */
+function sameValue(held: string | number | null | undefined, option: string | number): boolean {
+  return held != null && String(held) === String(option)
+}
+
 /** How wide a content-fitted menu may get before it stops reading as a menu. */
 const MENU_MAX_WIDTH = 420
 
@@ -92,7 +106,7 @@ export default function CustomSelect({
     return () => document.removeEventListener('mousedown', handleClick)
   }, [open])
 
-  const selected = options.find(o => o.value === value)
+  const selected = options.find(o => sameValue(value, o.value))
   const filtered = searchable && search
     ? (() => {
         const q = search.toLowerCase()
@@ -232,7 +246,7 @@ export default function CustomSelect({
                     </div>
                   )
                 }
-                const isSelected = option.value === value
+                const isSelected = sameValue(value, option.value)
                 return (
                   <button
                     key={option.value}
diff --git a/client/tests/unit/mobile/trip/MTripSheets.members.test.tsx b/client/tests/unit/mobile/trip/MTripSheets.members.test.tsx
new file mode 100644
index 000000000..f20b001f2
--- /dev/null
+++ b/client/tests/unit/mobile/trip/MTripSheets.members.test.tsx
@@ -0,0 +1,103 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import userEvent from '@testing-library/user-event'
+import { http, HttpResponse } from 'msw'
+import { server } from '../../../helpers/msw/server'
+import { useAuthStore } from '../../../../src/store/authStore'
+import { useTripStore } from '../../../../src/store/tripStore'
+import { buildPlanner, buildShell } from '../../../helpers/mobileTrip'
+import { buildTrip, buildUser } from '../../../helpers/factories'
+import { resetAllStores, seedStore } from '../../../helpers/store'
+import { render, screen, waitFor } from '../../../helpers/render'
+
+// FE-MOB-SHOST-030 to FE-MOB-SHOST-031 (001 to 029 live in MTripSheets.test.tsx)
+//
+// The phone has no share sheet of its own: the Mehr sheet opens the desktop
+// TripMembersModal through this host. Every other sheet is stubbed away so the real
+// modal is what the phone user gets (#2478).
+
+vi.mock('../../../../src/mobile/screens/trip/sheets/MPlaceSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MDaySheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MDaysSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MAccommodationSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MTransportSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MBrowseActionsSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MMehrSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MExportSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MNoteSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MImportSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MPlaceEditSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MReservationSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MTransportFormSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/sheets/MCostSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/roadtrip/MRtStopSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/roadtrip/MRtStaySheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/roadtrip/MRtKindSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/roadtrip/MRtInfoSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/roadtrip/MRtCorridorSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/trip/roadtrip/MRtDraftSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/mobile/screens/settings/MConfirmSheet', () => ({ default: () => null }))
+vi.mock('../../../../src/components/Planner/BookingImportModal', () => ({ default: () => null }))
+vi.mock('../../../../src/components/Planner/AirTrailImportModal', () => ({ default: () => null }))
+vi.mock('../../../../src/components/Planner/TransitJourneyModal', () => ({ default: () => null }))
+vi.mock('../../../../src/components/Trips/TripFormModal', () => ({ default: () => null }))
+
+import MTripSheets from '../../../../src/mobile/screens/trip/sheets/MTripSheets'
+
+const owner = buildUser({ id: 1, username: 'owner' })
+const alice = buildUser({ id: 2, username: 'alice' })
+
+function openShareSheet() {
+  const planner = buildPlanner()
+  render(<MTripSheets planner={planner} shell={buildShell({ sheet: { id: 'members' } })} />)
+  return { planner }
+}
+
+describe('MTripSheets share sheet', () => {
+  beforeEach(() => {
+    resetAllStores()
+    seedStore(useAuthStore, { user: owner, isAuthenticated: true })
+    seedStore(useTripStore, { trip: buildTrip({ id: 1, title: 'Japan 2026', user_id: owner.id }) })
+    server.use(
+      http.get('/api/trips/1/members', () =>
+        HttpResponse.json({ owner: { id: owner.id, username: owner.username, avatar_url: null }, members: [], current_user_id: owner.id }),
+      ),
+      http.get('/api/trips/1/share-link', () => HttpResponse.json({ token: null })),
+      http.get('/api/trips/1/invite-link', () => HttpResponse.json({ token: null })),
+      http.get('/api/auth/users', () => HttpResponse.json({ users: [alice] })),
+    )
+  })
+
+  it('FE-MOB-SHOST-030: the user picked on the phone shows in the field before the invite is sent', async () => {
+    const user = userEvent.setup()
+    openShareSheet()
+
+    const trigger = (await screen.findByText('Select user…')).closest('button') as HTMLButtonElement
+    await user.click(trigger)
+    await user.click(await screen.findByRole('button', { name: 'alice' }))
+
+    expect(trigger).toHaveTextContent('alice')
+    expect(screen.queryByText('Select user…')).toBeNull()
+    expect(screen.getByRole('button', { name: 'Invite' })).toBeEnabled()
+  })
+
+  it('FE-MOB-SHOST-031: sending the invite adds the pick and frees the field again', async () => {
+    const user = userEvent.setup()
+    let body: unknown = null
+    server.use(
+      http.post('/api/trips/1/members', async ({ request }) => {
+        body = await request.json()
+        return HttpResponse.json({ success: true })
+      }),
+    )
+    const { planner } = openShareSheet()
+
+    const trigger = (await screen.findByText('Select user…')).closest('button') as HTMLButtonElement
+    await user.click(trigger)
+    await user.click(await screen.findByRole('button', { name: 'alice' }))
+    await user.click(screen.getByRole('button', { name: 'Invite' }))
+
+    await waitFor(() => expect(planner.refreshMembers).toHaveBeenCalled())
+    expect(body).toEqual({ identifier: 'alice' })
+    expect(trigger).toHaveTextContent('Select user…')
+  })
+})