Anyway, after I copied folders to the new Seagate Backup Plus, I moved to my MacBook to copy files from that but it wouldn't let me. I didn't want the entire iMac backup as I have a drive specifically for that via Time Machine. But while macOS can read NTFS drives by default, its write capability hides behind a Terminal hack.
Is your external hard drive showing up as 'read only' on your Mac? Sometimes you may need to write some files to a locked drive only once, and you can do this with built-in Mac tools.
