Without even getting into the lack of quarantine...

Putting a male in with 2 females (especially if he's a first-year male) could be very intimidating for him, especially in a new situation. Moving animals from place to place is not always the smartest thing if you want them to reproduce. While it usually affects females more than males, a move may occasionally turn a male off for some period of time.

After your QT period, try pairing him up with one female at a time for a couple of days at a time to see if he'll be receptive. Split them up, give him a couple of days down time & perhaps offer a small meal, then try again after he's had a day or two to digest (if he'll even eat).

Breeding snakes usually requires a bit more finesse than just chucking a male in with a couple of girls, crossing your fingers & hoping.

There are a couple of excellent books - not to mention a plethora of posts on this very forum - that detail the mechanics of ball python reproduction & behavior. Well worth a read!