Did you leave some leaves attached to the scion wood? When I received some scion wood in the mail, the leaves on top were left intact, but I removed them when I grafted it. Not sure if I did that wrong or not.
I removed all the leaves on my scion wood, I think this is normally done (that I know of...). but I wrapped it all with "Buddytape", which I find to be superior (stretchier, thinner yet stronger) than the less expensive "Parafilm tape".
The age of your Hasya tree may have some role in it's inability to set and hold fruits. From a 15G tree with lots of flowers that I planted, after 2 years; -even with my manual pollinations help from me-, it only produced one lonely fruit each year! Now, it's on the 3rd year, only less than a handful of Hasya are hanging atm, while my 2 Alano branches have plenty, and I think they are self pollinating. I can say that this Hasya tree had been my biggest disappointment...considering the price I paid and the amount of work/care I gave..., but things are looking better now, with my converting program ongoing...
Jeff, you are in a different league! Besides of your superior knowledge of caring trees, you also have much improved soil I noticed, and lots of sapodilla trees (9 or 10?) in a cluster that may also contribute the pollinations, (I only have 1 tree) on top of that you are in Florida, so lots of humidity too...Jealous! But thanks for your helpful inputs, I always value them...!