There was a boa at a reptile store here, that did that. And when you help him he did the same thing. I think they called it ATB? Some combination of 3 letters, someone chime in with the right ones, lol.
But it's basically something that can't be fixed, and typically gets worse and worse.
Or it could just be a quirky snake, depends.
I don't mean to be a vulture, but it's what I do, if you end up having to put him down, please contact me, ....![]()