Unwanted changes of the screen resolution

Since playing around a bit with the Notch Bar support, I've been having a persistent problem with the screen resolution. I am not aware that I could have made any other changes.
I have now completely disabled the Notch Bar feature also deleted all actions... nevertheless BTT is shrinking my screen when I use the snap area functionality causing a black bar to appear at the edges.

btt contains no code to change screen resolutions, maybe some other app?

No, its definitive BTT.
It starts when snapping a window (I have no other app with this feature installed) and recover the old resolution when I quit BTT. I never happens when I am not running BTT.

But maybe its not a real change in resolution but a kind of shrink/zoom.
In the end a black bar in the size of the notch bar appears left, right and at the top.