Sounds quite normal to me, my snake did this quite often the first few weeks, and still does it occasionally.
You mentioned that you're using a non-regulated CHE
Out of curiosity, what are your temps? hotspot, warmside ambient, and cool side ambient?
I honestly believe that ball pythons prefer cooler temps than most keepers provide, or than the industry standard from a few years ago.
If you look at posts from a few years ago, many keepers advise 90+ degree temps, but in all honesty, I think ball pythons prefer hot-spot temps of around 88 degrees