StreetComplete shows me no map, just quests on a blank canvas. OSMand shows my offline maps just fine, but apparently StreetComplete has no way to reach the offline maps. I suppose that’s down to Android security -- each app has it’s own storage space secure from other apps.

In principle, we should be able to put the maps on shared SD card space and both apps should access it. But StreetComplete gives no way in the settings of specifying the map location. And apparently it fails to fetch an extra copy of the maps as well in my case.