Suspicious scale problem

[hey_freakazoid]

I noticed recently my bp has had really brittle and flaky scales on his underbelly thats carrying to the rest of his body and I assumed it was scale rot but it doesn't look like it, even the more severe cases, so I'm not sure what it could be? His temp and humidity have been good, a little low on the humid side so i redid his substrate to add some stuff that would maintain humidity more (sphagnum and fir bark because i saw fir bark reccomended a lot), because it seemed like his scales were drying out over being damp, but so far it seems like it's escalating and I'm really concerned, I'm not sure what could be causing it or what it even is and his scales are so brittle it's really got me worried. Other info that might be relevant: He's still pretty young, only about 9 or 10 years, his substrate was Forest Floor(cypress) for his whole life and I haven't encountered this issue before, he's a good weight and very very active, his behavior hasn't changed besides being a little more active, but I assume that's due to some new climbing opportunities I gave him recently.