Thanks for the report @Beaker! We were able to replicate this, so we’ve reverted to 2.1u while we investigate further.
The update took @Beaker’s switch offline. It seems to cause an issue with a small subset of SFP+ modules, or at least the visible symptom is related. We actually had trouble replicating this one, just luckily made it happen once, but that occurrence was enough for us to make this decision, especially being the weekend.