It's too dry. Notice in the 3rd photo from the top how the new growth is wilted over. No question it's too dry. That new growth needs to be turgid and upright.

That's a very big tree to move this late into summer. You are going to need to keep the original rootball wet all summer. I'd expect the rootball needs soaking every day. If your native soil drains well that won't be too wet.

Make a berm around the tree extending past the rootball. Use that to soak the area. An occasional soaking out further will help the tree establish a larger root system. It needs roots well into the native soil before the tree will really grow. For good nuts pecans need lots of water all summer long. One third inch per day out past the dripline on a big tree. When it's 100F plus 0.5 inch per day. But that's 5-10 yrs down the road.