I would suggest you heat it more than you think you need to. Not cook it, don't boil it, but it should feel warmer than you and quite noticably so. Even flash boil it by dunking it (or the head) in and out. This has been the major issue I have converting. Some snakes will eat thawed/warm snakes. Others need the dance and they also need some steady heat for them to register. Especially at first because dancing it around gives it more time to cool off.
But honestly, expect it to take some time. These snakes go 6 months at a time without eating and are fine. Stop stressing it, keep offering down to once a week and let it go