Grumpy Ball Python

[tttaylorrr]

you're very welcome.

1. I use a a digital thermometer from Lucky Reptile (https://www.amazon.de/Lucky-Reptile-.../dp/B002CWWR2S). It's a bit imprecise.
Inside the hide it should about 90 degrees. The hide is right under the heat lamp but the sensor is a bit further away. That's why it's often a few degrees colder. I've put the sensor inside the hide a few times when he was in the other one and the temperature was always fine.
There's a thermostat attached to the heat lamp but has never become active since the temperature is really stable. It's programed to stay between 31 degrees Celsius and 34 degrees Celsius which is, as far as I know, the right temperature for a ball python.

where is the thermostat probe located exactly? can we see a picture of your setup? a picture might give us a better idea along with your descriptions.

2. The hide situation is a bit more difficult. Someone gave my an old hide when I first got my ball python and I thought it was a good size. Since I read that it's better to have identical hides, I bought the same model but for some reason the new one was slightly smaller (but just barely, almost not noticeable).
Now I've bought two new (identical) ones but I've only replaced the one on the hot side because I thought that could encourage him to leave the other one. He still fits into the smaller hides but if he grows any bigger, he will lift the hides up.
I thought of changing the bigger hide to his smaller hide again(the one I replaced) but I'm afraid to stress him out because he seems quite stressed already that's why I didn't change it again. That's also the reason why I haven't replaced the other hide yet.

i say just swap the hides out for the new identical ones, then give him a couple days undisturbed and see what happens afterwards.

3. I'm not sure what a CHE is but I use a heat lamp. I've used it for 4 month (that's all the time he's been in the terrarium; he was in quarantine before that) and I haven't experienced any problems with it up until now. It's an infrared heat lamp. I know that he can see the infrared heat but I've done lots of research and found this to be the best way to heat his terrarium. He has not had any problems with the bulb all this time I had him in my terrarium.

CHE = ceramic heat emitter. it is a ceramic bulb that produces heat but does not produce light. CHEs tend not to dry out the enclosure as much as IR bulbs do, but if yours is working for you that's just fine.

i feel there's quite a few factors happening at once, so we can't really isolate an issue. maybe photos of your enclosure can help. TBH i think it's weird that, when he does go over to the warm side, he sits RIGHT under the lamp. this behavior makes me think his hide is just not warm enough, so he needs to sit on top and exposed to regulate; once he's warm, he immediately gets to safety.