Based on all the testing that I have done personally on Dell blade and rack server here in house @ EDGE, I've only personally seen a similar issue only once before, and it was after a PERC controller firmware update on a 12th Gen R720xd. Like your situation, I was able to simply import the "foreign" configuration and the system was back to business as usual. It's actually still up and running Ubuntu now, months later, without giving any indication that the "error" ever even occurred.
Given that the issue appears to currently be resolved, I would still agree with Dell that this could easily be a one-off fluke. That being said, please keep and eye on it and please update this thread if anything unusual occurs with those drives. You can also e-mail me directly at [email protected] and I will be more than happy to in any way I canto get the situation resolved for you. Thanks!