To make a small update here in case anyone else is seeing this, so far we’ve found that this was another case of the bug in this post where scheduler events were duplicated when they occur from 11:30PM to 11:55PM.
I’m running some tests tonight to see if I can get scheduler events to fail when they are on that schedule – the user in the linked post didn’t see that so it might not be the root cause here, but it’s a good thing to check.