The map settings fields hold what the user is editing rather than what
useTileUrl already resolved, so the preview received a bare template with no key
on it. resolveTileUrl then read it as a keyless CARTO url and did what it is
meant to do with one: fall back to the app default. The preview drew
OpenFreeMap while the fields said CARTO, whether or not a key was saved.
Same reason the tab crashed for anyone on a CARTO basemap even after entering a
key, which is the loop that made this hard to escape: the key is entered on the
page the fallback had taken down.
FE-COMP-MAP-033b pins the template the preview is handed, with and without a key.
Maurice
1984e151c1