You CAN use AI responsibly, it’s just not worth doing, most of the time. It would cost more than just not using it in the first place.

Specifically, they mentioned Poplars and Willows. Perhaps more, but I hit the paywall, couldn’t read the whole thing.

This might be thermistor losing contact with the block or wires losing contact. It can also be the heater wires losing contact somewhere. To diagnose, you can try and wiggle the wires when you preheat the hotend and watch the temps. Then you will know what needs replacing. I once had a thermistor that was faulty, I replaced it, the problem went away.