[Darryl Ramm]

Workspace:Volumes... Set the volume to playback or record depending on what you want.

If all this is greek to you, it's all in the Pro Tools Reference Guide.

Now did the Record/Transfer/Payback settings just get corrupted? Or accidently changed? Or is there something else wrong?

Still problems try trashing prefs.

That not the issue.. is the drive mounted read/write in macOS? (no "rdonly" option shown in the list within the () as when you run the "mount" command in the terminal. Do the contents on the drive look OK from the finder?

Anything else you changed recently?

Any other errors or weirdness?

EDIT: And hopefully you have a SATA SSD in that external drive... but even then I probably would not be putting samples and session files on a shared SATA drive. Not that it will cause this problem..