I know for sure that the one this morning was a traditional inclusion at the panel itself.
That’s good to know and answers the question I would have.
Looks like you turned everything off at once via a scene last night, is that correct? Did anyone interact with the light after that?
Can you confirm 100% if the Living Room Mantle device actually turned off when that command was sent or could it have begun this fade-in and out at that time?
There are no subsequent commands or reports from the system regarding that device after that scene off command. No dimming levels set, no all-on/all-off. This means it is likely a local phenomenon to the switch.
If all the affected dimmers are the same model that would at least make a little more sense to me, though I am not sure yet what would cause it exactly.
One thing to make sure is to update your panel firmware to the latest. You currently show 4.1.1
You’ll need to update to 4.2.1 first, then to 4.3.0. Does the behavior happen to stop after updating?