CPack (rpm) prebuild jar file changes checksum

I would like to generate a rpm package using cpack.
I’m using install(DIRECTORY … DESTINATION …) to also install a bunch of prebuild jar files.
But after rpm generation the packed jar files got modified and don’t have the same checksum as the original prebuild ones.

This is a problem, because later on I’m checking the checksums of the jar files.

Changing the files from .jar to e.g. .jar.bak and installing them will prevent the modification.

install(FILES … DESTINATION …) has the same behaviour.

Am I missing something?

Tested with latest version cmake-3.29.6-linux-x86_64

I tested it with a lot of other file extensions and only jar seems to be affected.

Is this an intended behavior of cpack?
Is it a kind of compression of the jar files (if yes, how to prevent it)?