I've done a fee searches and drawn a blank so far, so let's see if anyone has heard of a disorder that fits what I think I'm seeing.

Bethan is our problem checkered, she barely eats and some of you may remember me posting about her spinal problem, and also that she's had several bad sheds now.
The spinal problem I think is probably autoimmune, the lumps on her spine are similar to arthritis, and she started with 2 visible lumps, now she has 6 or 7. So it's a progressive disease.

Anyway, that's background as this post is about her shedding. We make sure that we see her at least every other day, and we generally see her each evening when she comes out to drink. We can be pretty sure that she has not gone through a blue phase, and yet she's retained yet another shed. I suspect that the last shed I helped her break didn't come away fully in the end and bits of that were stuck like glue. Now it's likely that she has another shed stuck, and this time I can't break it in the same way because my attempts with a scalpel this time are distressing to her.
What's making me think that she has a biochemical imbalance is that she hasn't gone through a blue phase, or her blue phase was so brief we missed it completely. I don't think it would be a great leap to believe that that a disorder exists that inhibits the production of the skin shedding lubricant, and consequently a snake is physically unable to shed when the new layer of skin is bonded to the old.

Has anyone come across this sort of disorder? I'll try searching more, but while I'm doing that I wanted to see if there was anything relevant in this collective knowledge pool.

I don't expect my search to help her, as I'm resigned to the fact I will need to put an end to her suffering once she is clearly suffering and shows signs that she has given up. It's academic curiosity now that makes me want answers.