As Nanci had said, totally normal. When is a snake is full, it will hide and digest. This is a heavy-duty thermal event. Some snakes can raise their body temps by as much as 13 degrees during digestion... So if they have a big meal, it may take a little longer.
Moulting also takes its toll. Basically the same digestive enzymes that the stomach uses to break down the prey will be released between the new "skin" and the old. This is what releases the moult. This process takes a toll. So basically you have your little guy working overtime
I wouldn't worry too much about humidity. My snakes get perfect sheds with around 40... so as long as you got it above that, you are good to go. If anything remains, get the area wet and it should peel right off as they slide against something. You don't need to put them in a rainforest
As long as they are healthy, the enzymes will do their work to release the old skin