@stevenjcee Same thing on Windows for me, haven't tried on Mac yet, it might be related to the latest update (which they include Workspace on sidebar along others).
Opera 67.0
Version: 67.0.3575.53
Opera is up to date
Update stream: Stable
System: Windows 10 64-bit
Use opera:about/ to find the precise version you have
This might help: https://help.opera.com/en/opera36/find-solutions/
I advice you to report that as a bug if you didn't already, beside that it would be good a representative to respond about this.
Good luck to us.
M.