MyPassport not seen by PR4100

Just got a PR4100 - very pleased with it. Also bought a My Passport Ultra to use with it as local backup. Plugged into back port but it is not showing up on control panel. My other USB drive is and works okay.
Should I format it first or what?


Do you have the same issue when you plug the drive to your computer.

Hi, no I just plugged it into PC and its fine.
But…when I plugged it back into server…in a different port on the back it is seen and works okay.


What’s the model number of the Ultra?
Which port doesn’t and does work? Is the issue repeatable with the port that doesn’t work?