For starters, 99 is a bit high for these snakes. Shoot for 90 in the warm side hide if you can.
I can't be sure about the scale thing but, I did have a snake in QT that had a bad shed before I got her. Being in QT I didn't realize I had missed helping with a few small bits of loose skin that became very noticeable pale spots as she approached her first shed with me. A healthy shed had her right back to normal.
Hopefully that is what you are seeing. The belly looks on the pink side, I'd spot check the hot hide with an IR gun to verify the temp and hope it is a pre-shed pink belly as opposed to a burned belly. A closer shot of that might help you identify which is the more likely case.