I’ve had a hotend that constantly clogged with looked like heat creep, but it was caused by the filament being pushed laterally and twisting inside it. I imagine that made the plastic flow back.
I have also had one constantly clog due to the print cooling fan being installed wrong and blowing into the heater. This one is weird because it just unclogs when you turn the print off, leaving no evidence of what happened.





Once a bubble is inflated, it never deflates slowly. You can inflate everything else. But the only way a bubble reduces is by popping.
That said, I don’t think it’s happening right now.