Slight Wrinkled PINK BELLY on bottom portion of my Ball Python snake

[TheButters]

Hello,
My beautiful ball python snake has been having slight wrinkled pink belly on the bottom 1/3 portion of his body.
He's about 1-2 years old, Butters just moved from LA to San Diego last Winter. He has shed twice already; I am aware that that pinkish belly happens when ball pythons shed however, even after shedding and eating his food I notice the pinkish colored bottom portion of his belly has not gone away since he has moved down to San Diego! (Meaning prior to that he hasn't had this problem before) So I am wondering Butter's having an Respiratory Infection or any other kind of disease. Addition to this happening Butters has been not able to attack his small/medium rat himself, so attempts but fails, then he gives up and I put his food away. I tried smaller rat today and he still couldn't attack it. He shed last week so there's no way he's not hungry/ about to shed.

I'm worried about his belly There's a slight brownish line (about 1 inch) on the start of the pink belly area... I'm wondering if that's...
I decided to take some photos of his bottom portion of his belly, please check them out and suggest what I should do! Thank you!

Photo 1:


Photo 2:


Photo 3: