I have a problem with workspace panels not showing up sometimes, or showing up but won't expand in order to use them after I launch Illustrator. The problem only affects the panels on the right, it never affects the toolbar or control panel.

I have had this problem over many versions of Illustrator, on different operating systems including fresh Adobe and Mac OS installs from scratch (not migrated) However I am currently on Mac OS 10.15.6 using Illustrator 25.1 and now very fed up with the bug.

A brief Google search shows others are having the issue too: https://community.adobe.com/t5/illustrator/workspace-panels-disappearing-and-or-not-opening/td-p/6781529?page=11

When the problem happens I can solve it by turning on the Application Frame, but I prefer not to if I can help it. Sometimes an immediate restart of illustrator can solve the problem, if not then trashing my preferences will always work.

I have also tried creating a new workspace and that doesn't help either.