@NilartPax, there was a discussion about the Z axis falling after a print completes. Although those sounded like they were relatively slow, and only really a problem when the print finished while unattended.
When your print finishes, is the descent powered or unpowered? It might be hard to tell the difference with the bed still moving. If you gently try to interfere with the descent, does it prevent the descent? I wouldn’t try very hard to prevent the descent, just a little bit of upward force to see if the module is being driven or if it’s falling due to gravity.
Do you have anything attached to the X axis? I printed a little box (I can’t find it on thingiverse) that attaches to the X axis and holds the CNC clamps, bits, pallet knife, and tweezers. I had to stop putting the knife and tweezers in there because it caused the Z axis drop. But it’s been fine ever since I stopped adding extra weight.