5.9-10 macOS 10.15.5 MBP 2020 preference mishap

Ok, got it. Resizing it does the trick, but only for the actual preference session.

When I close preferences and open again, it's all back to what it was before and with that the bug.

If you close with OK and not with Cancel, it should then remember the size for the next time.

Ok, thanks. This fixes the problem.

This is a turn around, but the cure is elsewhere, we still need to investigate.
If you have the time can you move the reduced dialog so it "touch" screen borders (especially bottom) to see if the bug is back?

Yes, I know. But at least a fix until problem is found.

As soon as I expand the preference window beyond the bottom status line, the bug is back. When put on top of the bottom status line, it works fine.

Hope that helps.