Sounds like it might be heat stress. Just give it some extra water, during that time. I'd also do a soil sample. My 10 year old tree never does this, and it gets full sun

Thanks for the comment, I will try that.

I would get a soils test to see if anything is lacking, or if there is a pH issue. I had a SS Plumcot in a container that would do that. I think it was a mineral or pH issue. I applied Chelated Iron on the leaves and in the container. I also applied epsom salt and lime. I couldn't get soils test since it was in soiless mix. I think with all the watering I had to do, it caused some type of mineral deficiency, but not sure which one.

The Harvey flood killed it but I had another one in the ground that survived, so I transplanted it to my new house and it is doing well.

I put a lot of water on it and it looks better already.