The foliage damage to your persimmon appears to be minor. The flower calyx is not an important structure at this point of fruit development, so as long as your fruit is holding and developing, I wouldn't be terribly concerned.

There are potential problems with your use of potting soil on top of a Houston Black clay soil. Potting soil is much more dynamic in terms of drying that the HBC, and it will be difficult to maintain in a mound or bed, unless you use some edging or landscape timbers. Persimmons do not need to be grown in a wet, poorly drained situation. Based on how you have set up the planting, it is possible to create a large pot effect. Poor drainage can result in off color leaves, failure to thrive, fruit abortion etc. A better approach would have been to create a raised bed with Houston Black Clay, thus having a continuum of soil that dries uniformly. In your present situation, as you water the potting soil enough to deal with its drying, you may also be holding water in the hole you  dug out of the HBC "for the roots to grow in".
I also notice that your first year tree is bearing fruit. Understand that fruit production for a first-year tree increases plant stress. Hopefully you survive this year, and have a stronger plant next year.