I just copied the file from the synced folder again, in order to create the zip-file and notized, that I couldn't do anything with it while I had minecraft open. So I now assume, that windows for some reason dind't copy the file but just created a link to it. So this may very well not be a problem caused by minecraft.
Kai Welsing
The file from the with one drive synchronized folder:
https://gigamove.rz.rwth-aachen.de/d/id/davPxy6ToWGujj
The file from the minecraft save folder:
https://gigamove.rz.rwth-aachen.de/d/id/WP4wwchVrRhSBR
I just copied the file from the synced folder again, in order to create the zip-file and notized, that I couldn't do anything with it while I had minecraft open. So I now assume, that windows for some reason dind't copy the file but just created a link to it. So this may very well not be a problem caused by minecraft.