I must have been blind 😅
And I mean, even worse than that, because I also searched the settings menu for "Drag", and I swear I didn't see it. Now, I couldn't miss it of course.
@guigirl said:
If you already knew how to disable it
Well, I managed to turn tab stacks on/off, but I never before found the exact setting @Ayespy mentioned.
I could re-enable tab-stacks any time, I just didn't want to, as that turned drag and drop back on - which is the setting I didn't see.
Anyways, thank you guys. Can the question be marked as solved?