matchboxbananasynergy I am experiencing the same issue, though it only seems to happen on Vanadium.
I'll have multilanguage support enabled, then open a Vanadium webapp, and the first time I open Gboard to type anything (I use a webapp for Signal Community Forums), it'll show up as single language, no swype typing is possible and capitalization doesn't happen on the first letter.
I manage to get it back to multilingual and how it functions normally by long pressing the language select then swiping back, at which point it returns to normal behavior.
It is reproducible consistently if you have Signal Community set as a Vanadium webapp on your homescreen, you open it, then you try to reply to a post.