Me! I’ve been meaning to play it outside to see whether or not it’s the combo.
Sorry to hear you're having similar issue. Mine now resolved - see answers to other Rumblers. Check all your cables and undo /redo. My room at home is not great, stuff does vibrate. I also wonder if a cable extension into the mains was contributing. Do you use the overdrive much? Cos I wondered if the circuitry/switch of that 'bleeds' the effect into clean signal somehow? My understanding of electrics is patchy.
I'd be interested to hear if yours persists/clears up....?

on a gig.
But, ... . . . .