After installing the add-on and restart of Firefox I can choose my 1Password Login, but only the username will accept, not the password. I have installed 1Password version 8.10.3
It is working with Chrome and Edge.

Love it when it works but constantly have to delete the extension and reinstall because of the unable to save item error. Garbage extension.

wow

1Password extension for Firefox grayed out and cannot install on tablet. Useless app

Because of breach and recommendations on other sites, I switched over with high expectations. The complaint is about "auto fill". When attempting login on my favorite sites I am forced to login to 1Password account.
Having contacted support and getting quick replies on how to deal with this issue, none of the suggestions worked. What did work was setting lock out time to almost three hours before app locked. Thus having to re-log in to 1Password account to fill UN and PW.
To say the least it is a frustration.

Stopped working! Total mess. No forms are filled in at all anymore, anywhere.

Did work like breeze previously, but last couple of months a lot of issues. Sometimes it works, sometimes I doesn't even allow me to choose a login to auto-fill in the browser. Complete random behaviour

Version 2.8.1 is completely broken for me. It's incredible how unstable this extension is. Sometimes it works perfectly for weeks, but then it's completely broken again. Unacceptable for a paid tool.

Barely usable. Constantly not syncing with browser, so I can't add a password in the app and then use it in the browser. Tried lock/unlock, no luck. Have to force quit both my browser and the app just to get it to recognize the change/update. No "Force Sync" option. Last several times that I attempted to "Save in 1Password" a login, the attempt to save it fails. Have to put it in, manually, to the app. Then - you guessed it - the browser has no clue about the addition. Lots of force quits, all over again. It's a nice system, WHEN IT WORKS, but the issue is that it doesn't. Moving to something else.

1P used to be the best for me. Just can't get the extension to work with 1password 7 anmore. Hasn't worked for months and can't find a get-around.
Given the new business model and obligation to synch on unknown servers, I'm moving to Bitwarden which is open source and much more reliable than this.