Some files on external hard drive not visible on M1 MacBook Pro

I'm trying to import my music library (that is, 18GB+ worth of MP3 files) from my Seagate external hard drive onto my MacBook Pro 13". The hard drive mounts just fine, and I can see a number of other files in the drive (JPG files, PDF files, etc.), but it looks like the MP3 are not visible at all.

I tried viewing the hard drive on another MacBook Pro (with an Intel processor), and the MP3 files are there. The Intel Mac can see them just fine, but the M1 Mac behaves as though the files don't exist for some reason.

Has anyone else encountered this issue? How can I view and import these MP3 files onto the M1 Mac? Thanks!