That's odd to hear! I certainly believe it, because I've had this issue with other password managers in the past - but I haven't come across this with Bitwarden on desktop. Mobile however, I definitely get issues where it won't prompt the autofill button on the keyboard, sometimes tapping the password field will cause it to realize its there, other times I have to use the quick settings tile to autofill.

You might be able to workaround the problematic sites though using their custom fields attributes for logins.

I still prefer it because then I can have teh app on the phone and log into wherever from it, and if I'm in a foreign pc I can log into the vault and copy the passwords. It also works across browsers, so the firefox at home and the edge at work are synced by default