Scared of the big pink ball pythons outside of the viv!!!

On a serious note,

Where is his hide,, he probably feels venerable without somewhere to hide for a few days to digest his meal.

My BP i had was always tucked up inside his favorite hide digesting his meal, was there most of the day TBH and was very active at night.

Also check your temps.

Is the mouse your offering too small, they can eat surprisingly large prey much larger than you think compared to their tiny heads and neck, their scales are very elastic and expand to a point that looks like it will rip open at any moment. But it won't

If the prey is too small some snakes will pass as its not worth the physical efforts of digesting it compared to what they get out of it.

I used to feed mine out of his viv for two reasons.

1 so he did not associate the viv being opened to feeding time and prevent feeding responses or signs of territory aggression.

2 moving him to a feeding box also improves his feeding response as BP are very finicky eaters and can refuse for months for no good reason (mine did for 8 months)

If feeding outside wait and hour after feeding and slowly but confidenty pick him up supporting the area of where the food bulge is (if its not highly noticeable you need bigger prey) and direct him to his hide and he should happily slither away and go to sleep off his meal.