Version 8 Autofills the Wrong Username

When I use the shortcut "Fill in Browser" for the desktop app in my browser (FireFox), 1Password always fills in the same details no matter the site, as if it thinks all websites use the same login information. The login is the first one that I used after updating. I was prompted to change the MacOS Security & Privacy > Accessibility setting and after that it was stuck. How can I fix this? I tried reinstalling but that didn't do anything (I guess I'd need to delete the local settings for it to have an effect?).

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1Password Version: 8.7.0
Extension Version: 2.3.3
OS Version: 12.3.1