@gnirtS Welcome to the forum!
And Sorry for the delayed response.
I just tested on my Android 15 device with Edge to login to this forum. I can autofill username and password without any problem. Passkey-login opens Google password manager first (usual gateway), but BW takes over and logs me in with passkey.
I have no direct idea, what it could be in your case… but there is a new post about autofill on Android I just posted yesterday - maybe that could give you a hint: [Short Guide / Tips] Autofill on Android
PS: @JasonB the same goes for you…