OK, another reason snakes hesitate (& refuse) is that they've gotten hurt in past encounters. That makes the most sense, since you're feeding live, & it sure
complicates your feeding plan, doesn't it? Just because you weren't aware of it doesn't mean your snake hasn't gotten bit (maybe just pinched-didn't draw blood)
when feeding. Some BPs have been known to reject all rodents of the same color or type after such incidents. It's one of many reasons to get them on f/t.
I'd recommend waiting a bit longer for next feed, then offer a live EYES-CLOSED rat pup (or mouse) first as an appetizer, & have ready
on hand a dead rat of proper size (remember you're giving 2 things so make sure size isn't excessive) and try to get him to take the
2nd item immediately after he deals first with the live one. 2 ways to do that: either chain-feed it to him when his mouth is still open,
nose of f/t to tail of one he just dispatched, OR, he might be pumped up enough to just eat it for you...cross your fingers & find out.
This way he learns to eat dead prey & after a few feeds will (hopefully!) just accept them on their own.