Safari extension still very slow to unlock :-\

Do you think this might be an available-resource issue on the system generally, or does the problem seem to be specific to 1Password?

Even after a fresh reboot, with almost nothing else running (just a few menubar apps that start at login) it's the same. My Mac mini has 16GB RAM and is running macOS Catalina 10.15.7 with Safari 15.3. I know it's considered old and slow by today's standards but 1Password 7 is pretty much instantaneous.

It seems to be worse on the first unlock after a period of not being used. Once it's unlocked it's mostly ok. And the sequence of events logging in isn't always the same. For example, this morning I got the prompt in Safari to Unlock 1Password (the app), which I did and then the Safari extension prompt was asking me to unlock 1Password from the toolbar. I did this too and then it got stuck on "Loading...", for minutes. Eventually I managed to get it to work by toggling the extension off and on and logging in yet again.