Plugged it in, and after a few minutes it decided not to install properly. The MTP USB driver or something.
Googled ... gazillions of suggested "fixes", none of which has worked so far, but all of which involve a reboot. So that's 6 reboots so far, none of which has fixed the issue.
I bet the second I plug it into a Linux box - *any* Linux box - it'll be fine.
I wouldn't mind if I could only access it as a USB drive. Right now, nothing.
All I wanted to do was move some audio files around.