Why has my hard drive started spinning-up each time I eject it? When I eject the hard drive, the disk starts to slow down but then the disk starts spinning at full speed about a second later. The hard drive is not mounted but it is still spinning. I’m afraid to unplug it when it’s in this state. If I wait about 10 minutes, it eventually stops spinning. I’d rather not have to wait around that long.

This only started happening about a month ago. It might have been due to a software update but I’m not sure. Why is this happening and how do I fix it?
I updated to macOS 10.14.4 and the issue has mysteriously resolved itself. A software update caused the problem and a software update fixed it.