The corners are printed differently than in the model and slicer

I get convex corners. The models are different, but I print with plastic RETG from different manufacturers,
the result is the same.
Everything looks great in the slicer. A seal with convex corners:

The bulges on the right angle corners indicate that the Pressure Advance (k factor) is not correct. I’d suggest running flow calibrations on your filament. I personally prefer Orca Slicer over Bambu Studio but either should work.

I made a calibration printout. Everywhere the corners are convex. I think the reason is different.

That is a flow rate test, not pressure advance. So it would make sense, if your pressure advance is bad, that you would see it in this test also.

Just do a flow dynamics test first and see. The automatic test does not work well, or better at all, on the textured PEI plates.

Edit: I just saw you posted it in the P1 forum, then the automatic calibration does not apply to you anyways.

Thank you very much, the calibration gave a positive result. The angles are great now!