Hrmm. Interesting. Was the drive NTFS?…only ever used on windows machines? If so…you’re praising Apple when macOS didn’t even fully support it. You lost your files because of macOS

Macs use HFS+ or APFS format, whereas Windows computers employ NTFS. FAT32 and exFAT are recognised by both Mac and Windows devices but those aren’t commonly used anymore. You can check the formatting by going to the Apple menu at the top of the screen and following About This Mac → Storage…i think?