On some sites autofill for firefox recognize and fill in the password field only, but not the user/id field as well. At the moment I saw this behavior on same banking websites only.
For example (but it is not the only one): https://www.dkb.de/banking
When I try it with Chrome instead, there is no problem.
I kindly ask you to keep an eye on it. ;-) Thanks!
1Password Version: 7.1.1
Extension Version: Not Provided
OS Version: Andorid 9
Sync Type: Not Provided