After trying as many suggestions as I could, it seems the one that did the trick was replacing the thermistor entirely. Seems I must have broken it somehow, though the glass bulb and wires were still intact from what I could tell.
Glass bead thermistors have very fragile wires and sometimes you can't see a break that has occured. I replaced mine with a cartridge as fast as possible, but good on you for finding and solving the problem.
After trying as many suggestions as I could, it seems the one that did the trick was replacing the thermistor entirely. Seems I must have broken it somehow, though the glass bulb and wires were still intact from what I could tell.
Glass bead thermistors have very fragile wires and sometimes you can't see a break that has occured. I replaced mine with a cartridge as fast as possible, but good on you for finding and solving the problem.
Well done and thanks for posting an update!
Next step do a PID tune, that looks fixed but your hotend graph should be way flatter than that with a new PID tune.
How flat should I expect it to get? It's sticking to +/-0.2° of the set temperature at the moment
Ok that fine then, thought that was more then it is.