We're having the same issue, two different users (one of them is me).
We had not used the extension before the upgrade to 7086.
API is working (password generator, graphs, and we use the API for other stuff too). Rebooted the machine hosting passwordstate, disabled/enabled the extension.
The developer tools window closes once you click save so I can't see if there are any js errors.
In the IIS logs I'm not seeing any calls to the API other than "/highavailability/GetPrimaryStatus", "/searchpasswords/" and "/generatepassword", no matter how many times I click save.