Cool. Thank you trs96!
OTHER THAN THE LACK OF DRAMA... I can't see myself spending that much for such slow drives, though I suppose to rationalize it, they do come with their own enclosures. Oh well.
So to wrap this thread up, to summarize I've run 54 setup permutations in an effort to eke out whether the culprit is something else. It seems really odd that I've bought 2 pairs of drives in a row that disconnect spontaneously, which makes me question whether there's something external (no pun intended) causing the disconnects and that the drives are possibly fine... but I shouldn't have to work this hard to give them the benefit of the doubt.
The facts remain, they do disconnect, and on this same system I have 2 other drives that don't disconnect and run fine, so I'll have to hang my hat on this and hope Amazon takes my returns and doesn't question it. They say they reserve the right to test "DOA" drives, but what they can't do is test on my setup, which, again, is a Mac Studio and they should work and play well with this computer and the enclosures I also bought on Amazon.
I'll probably wait for the WD drives to come down (Have set up an alert on camelcamelcamel).
Wish me luck!
