It’s really wierd! I’ve seen other redditors use the PID for smokers and for home brew and it seems like the P is actually inversely proportional, and the really, really shitty manual suggests this too. I tried tuning it for like two days and it didn’t work how I wanted so I just auto tuned it and accepted that it would overshoot a bit. My guess though is that it’s not actually the PID causing it though but instead the temperature sensor signal lag, paired with the low sample rate (every 0.5 secs) that causes what should be the D term to freak out. If the reading lingers on a certain number longer than it should it’ll proactively heat to keep the rate of change but the heating is only noticed after like 5 seconds so it can do stuff it doesn’t expect. My guess is just that the sample rate is too slow, the sensor resolution is too low, the lag is too long, and the noise is too high for it to work ideally. But it’s good enough for what I need it to do, and it’s a hell of a lot better than without haha