As others have said, be patient.

Now, you don't have to cool them at all if you don't want to, and low 70s is way too cool for a ball python, even for breeding. I never cool and my tubs stay in the high 80s to low 90s all year round. This will be my 4th breeding season.

It is still really early in the season. Last season I didn't even begin pairing until mid to late November and that was only one female. All of the other females began pairing later. And I got 3 clutches out of 3 breeding females, so it takes patience. They might be locking a ton but you just don't see it. The best thing to do is to leave them be and during the time the male is not being paired with the female, just watch her for development behavior such as wrapping around her bowl, seeking the cooler side of her enclosure, laying on her side. Those are good signs, and are less intrusive than opening the cage all the time trying to catch them in a lock. Locks can last anywhere from 5 minutes to over 24 hours. It depends on the snakes and you may never see them lock but one day come home to find your female is ovulating.