Thank you. That didn't work, "Settings" was not listed anywhere on the left (or anywhere else). But when I went directly to URL opera://password-manager/settings by typing it into the address bar, it did. Thanks.
A new version of the opera was released on January 4, 105.0.4970.74. I deleted the old one and installed this one, everything worked. Guys, if you are tracking the group, I recommend restarting it. I don't know what they changed, but now everything works.
@docforbin Or if that seems a bit of a faff, you could just search for updates via 'update and recovery' and if that doesn't work do an Opera refresh on the same page. You will lose some of your settings but these are quite easy to put back and you don't need to be a tech genius to complete the task. This worked a treat for me and took me 5 minutes (including putting my preferred settings back).