Hi @denismaier,
For determining version #, please see the post here: How do I determine my PKP software's version?
With your link, I was able to see that you’re running 3.3.0.12.
As for your issue, I note that this is already an open issue/feature request here: Add an option to enable/disable categories in submission workflow · Issue #6306 · pkp/pkp-lib · GitHub - it does look like work is being done on improving this in OJS version 3.4 (due out early in 2023).
-Roger
PKP Team