If I am reading things right, his weight and weight loss seem fine. Fasting duration is fine. Really need a picture to see how he looks in a length to weigh comparison. Your cool and hot sides seem to be far apart. Cool is too cool and hot is too hot. Humidity is low in my opinion. Setup seems a little imbalanced. Post some pics so we can help you out.
See here
https://ball-pythons.net/forums/show...ius)-Caresheet