I've noticed autofill not doing anything on some of my own sites. (Also see same behavior on https://bmxmuseum.com/forums/login.php) I can't see any issues with the forms that would be causing this. I even added autocomplete attributes to username + pwd fields to see if that helped, but still no luck.
Steps to reproduce:
Go to https://microcosmpublishing.com/login
cmd-shift-o, create new password for microcosmpublishing.com with test/test
Try to autofill. Nothing happens.
Username and password autofilled.
Orion, OS version; hardware type:
Version 0.99.113.2-beta (WebKit 613.1.12), 16gb M1 Air, macos 12.3.1