Can you check the Nextcloud log for login errors. (Entries like Warning: Login failed: username (Remote IP: 127.0.0.1)). The reload-icon spinning for so long and then just stopping sounds like previous failed logins triggered the brute-force protection and now the extension runs into a timeout while trying to fetch data.
Maybe it would help if you open chrome://extensions/ and click on “Background Page” of the extension and check the Console for errors and the Network tab for failed requests.
You can also run this command from the console to check if the app password was actually saved: chrome.storage.local.get(function(result){console.log(result)})
My mistake. It is working – the arrows just don’t stop turning, but it does indeed sync with an app password. Sorry to trouble you. Two additional things:
it would be nice to be able to add passwords from the extension
it doesn’t always detect when I type a password and prompt me to add it. In fact that happens with reasonable regularity.