Mac OS Safari 1PW extension installed but not listed

Hi,
I can open 1PW extension from App Store, get pop up window to Open Safari preferences and start using the 1PW extension. Yet, if I go there, no 1PW extension is listed to select.
Also, on your support page for Safari, I have warning "1PW is not installed in your browser. Install it now".
Clicking Install it now just repeats the above, App store with the only option to Open the extension (not update or install) and gives the pop up window.
So App store behaves like the extension is installed, but under Preferences in Safari there is no 1Password extension listed.
I have rebooted both 1Password, Safari and whole Mac, no change.
1password app itself works fine and I can copy/paste user names and passwords.
Also the extension worked fine before this 8.10.46 update I did today. Might be an old MacbookPro 2013 with BigSur 11.7.10 as the latest OS available.
Thanks

1Password Version: 8.10.44
Extension Version: 8.10.46
OS Version: 11.7.10
Browser: Safari