My bearded dragons tail looked like this, I found out that it was his feces that his tail dragged through. Have you tried to wash his tail? I know chams don't like being messed with but just a thought.
I as well have a timer on mine.
I would wake up earlier but at the rate I'm growing at (13) I'm always tired (maybe that's the reason my cham doesn't move much he's like me a teen and growing fast!!!)