DeletedUser87 oh yes, i confused your comment a little. Actually this issue is only a part of the autofill /spelling service i am not sure which one of them is dominating in system hierarchy please correct me if i got it wrong. Let me put it in a nice easy read in case if someone has similar questions.
So i noticed the Vanadium's PW manager auto sign-in toggle mystery a while ago, before i asked for help here. and while following users advises for mitigation or advises to test related functionality i immediately noticed some changes in functions that i never thought are related.
Such as spell checking, corrections , i had mine only recently straightened out and starting the auto sign-in investigation spelling suddenly broke. later it made sense, i figured "Suggesting" is a point of there relativeness.
I am a fan of florisboard keyboard for many reasons, and was always in pain from their spelling support lacking. And recently while submitting some issue on git, another user advised me to try another keyboard that they stated has spelling intact i shacked it out and fell in love, spelling turned out not being able to piss me off most unctions seemed at par with florisboard the font i like actually eben better than florisboard's. but short was my party. i found out that it's clipboard is system-wide fully shared (and no setting to adjust this)vs florisboard's clipboard having options to be accessible only for the florisboard itself or be connected with system clipboard offering flexible results, in few even a single reason for concern a few years I'm on it since 2020 for sure, prob earlier.
This fact gave me next task, that got resolved somehow easily on the go, to have both benefits in one package. i accidentally came across an option in settings to set that suggested keyboard as a spelling service for florisboard. This happened during my trial and error research of Google or third party autofill devices being set in Vanadium