Answer: This tree, Diospyros digyna, typically begins to bear about 5 years after planting so the tree may still be a bit immature to carry a fruit crop. In a brief seach I found some information about this tree from the World Agroforestry Centre in which it mentions potential pollination problems. Apparently some, but not all, black persimmons produce self-incompatible flowers. This means it is possible that you will need two trees that bloom at the same time in order for pollination to succeed.
You may find their article about this tree helpful. It also mentions that the mature tree is quite large, for example. (You may need to cut and paste the complete url into your browser to make it work correctly.)
Congratulations on keeping it going so far and best of luck with your tree!
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