I have two Windows 10 laptops and I use 1Password on each for the same user, myself. One laptop has the old 1Password extension for Firefox and the new one has 1Password X [1PX from hereon]. I seem to have no end of problems with 1PX. It constantly cannot find existing logins, suggests the wrong ones, doesn't attempt to store new logins and the password generator is MIA. I am very frustrated with it and have even deleted it and reinstalled it, but no progress. If I could go back to the old extension I would do so in a heartbeat. I don't have any such issues with the old version on the other laptop and there is no way I will upgrade it to 1PX anytime soon.
Hopefully there is a new and working version coming out soon.
1Password Version: 7.6.778
Extension Version: 1.20.0
OS Version: Windows 10
Sync Type: Not Provided