@damienuk I'm in the proces of moving to FF.
With the Workspaces extension it seems to work fine.

Opera version: 106.0.4998.52 MBP M1 14.2.1
Same problem here for many months and updates.
I usually occurs after having downloaded a file.
Right click does not work anymore, have to click twice to close a tab and quitting Opera only possible with a Force Quit.
The only way to solve this is to restart Opera (sometimes multiple times a day...).
Very very annoying!