Comment 17 for bug 1572121

A workaround that seems to help in my case:
cd “folder path” (in which you want to change permissions of the files)
find . -type f -exec chmod -x {} \;

Source: chmod - How to remove executable bit recursively from files (not directories) - Super User
https://superuser.com/questions/234647/how-to-remove-executable-bit-recursively-from-files-not-directories#