Dear Maintainer, Quodlibet doesn't remember panel positions and sizes after
restart.

What did you try to do?

Preferences -> Column Layout -> Wide

Expected Output:

The panels remain in wide configuration after restart.

Actual Output:

The panels go back to the "normal" configuration.

Solution:

Downloading and launching quodlibet 4.4 once solved the problem,
even for the system wide 4.3. See
https://github.com/quodlibet/quodlibet/pull/3365