Typically file system causes that, usually no worry
Sometimes due to storage formatting (exFAT, APFS, HPS, NTFS, ext4,...there are many)
RIFF Header information is the number to track
Calculating the MD-5 or a SHA hash number and comparing is the best way to verify file integrity.
Headerless audio can be 'Imported' in many programs, 'Open' uses existing calculations in the header, import does its own, if I understand it correctly.