I don't know what could have changed with him but there is a couple of things I would change.

I would get him on some type of light cycle. Get a UTH so you don't have to have the lights on 24 hours a day. Make sure his temps and humidity are correct. I think he would be happier with a hide on each end of the tank so he can have a choice.

Also I see smoking around an animal as abuse. He doesn't have a choice and can't escape that. Opening a window might help clear the smoke but it's also changing the temps and humidity in the room.