The files themselves are most likely fine, it is the flags on itch that have been confused.
Itch thinks the the mac file is for linux and the pc file is for windows .
I am guessing the mac file should be flagged for mac and the pc file flagged for both pc and linux.
As it is now linux users using the itch app will get the mac file when downloading which wont work for them and the mac users might not get a download option in the itch app.