External SSD not showing up at startup
Since updating to Catalina and also shifting to a new SSD external drive (from SanDIsk) on my 2015 iMac, the external SSD drive does not show up on startup. I don't just mean that it doesn't mount. It shows no presence at all (that is, it doesn't show up in Disk Utility even as unmounted).
The work-around is simple. I disconnect the cable connecting the drive to the Mac and plug it back in again. The drive then mounts as normal. And all is good until the next restart.
It's a minor hassle — especially since I don't often restart. But it shouldn't do this. And I have never seen this symptom with any other drive I've used over the years. I have a similar problem with another SanDisk SSD drive connected to my 2020 MacBook Pro.
Is this a known problem with SSD external drives? Is there a known solution? Thanks.
iMac 27″, macOS 10.15