Atemoyas not bearing fruit

[Nuschka]

I live in zone 10B in Florida. The first year I had three beautiful and delicious atemoyas. After that, it’s been 3 years and after the leaves fall, the fruit doesn’t develop, dries and falls down.
I’m even polinizing them myself and putting fertilizer every 3 months to no avail.
What am I doing wrong or what else should I be doing?
Thank you