Hi wickfyt! Thanks for the hint about restarting the computer - it works for me. It’s not ideal, but at least now I have a workaround. Thanks!
What’s interesting is that for me the problem went away after upgrading from 9 → 9.5, but it soon returned after I upgraded Windows to Fall Creators update. I’m sure this is Windows related, but Steinberg should have a way to fix this. After all, all other apps I use don’t have these kind of problems with their cursors.