I agree with Luvyna's post above, &
Also, you said "you've kept handling at a minimum, especially as of lately": that might be the problem...handling a new snake before it has settled in enough to
eat reliably (at least 3 times easily & on schedule) is asking for trouble, especially with the typically-shy ball pythons.
Offering weekly might still be too scary, too much "chaos" for him yet...maybe don't offer for 2 weeks. Wait until evening...not when he's cruising his cage, but
hopefully when he's peeking out of his hide (BPs are ambush-hunters...they like to feel safe, laying in wait for a clueless rodent to go by). Are you using tongs to
offer food? (please do) You might be doing too much motion & scaring him off: you want the motion to be subtle, not "waving it around". Never approach the
snake with the prey either, but make it look like it's just strolling cluelessly past where the snake is. Also, rodents cool off fast...once thawed, dip the head in very
warm water briefly &/or blow dry it right before offering, before it can cool off too much. BPs can be very picky, needing it to be lifelike to fool them. You may
sadly need to feed him some live before being able to switch him, as it doesn't sound like he was completely won over to f/t when you got him.
We know the frustration...hang in there! Some snakes (many BPs) really tax our patience.![]()