How to de-stress a ball python?

[AkHerps]

My ball Python has been doing great for months and months up until just recently. Nothing in his environment had changed but he stopped eating for about 3 weeks, and then on the 4th week he ate his usual f/t small rat with a very strong feeding response. He had completely outgrown his hides so I made him 2 new ones, completely identical. They are just Tupperware containers with dark krylon spray paint, water sealed with a matte finish and dried for a couple days before going into his house. I hot glued some smooth flat rocks on the top of them to weigh it down because they were sliding all around his tub, and hot glued a little bit of fake plant on it, mainly for my effect haha I don't think they are too big, because when he has gone in them, the sides of his body touch the sides of the hides, but he isn't hanging out of the hides.

But regardless, he has been roaming around all the time now, and sleeps in between the hide and the wall of his tub, and refused another rat today. He seems really interested in them and goes towards it like he wants to strike, and then loses interest. I don't hold him too often, maybe once a week, sometimes twice, so, handling isn't the problem I don't think.

He is about 3 feet long, and I think he will be a year late this June.

Any suggestions? I'm not really sure whether to try to get new hides, or what? haha

He's also always very cold when I do check on him. I check his temps daily and they are always spot on.