Thank you for the images.
It's very likely the tree is short of water. That could be true even if you are watering it.
When moving a plant from one container to another, the origianl rootball should be thoroughly moisten and the added potting soil should also be moist.
To accomplish that:
1.) Submerge the rootball in water until bubbles stop rising, a maximum of 20 minutes; remove, drain and plant.
2. Pre-moisten the potting mix until damp, not sopping.
1.) Followup care may require daily watering during the first weeks) to the original rootball if the weather is warm and breezy, perhaps every other day when it's cooler. Feel the surface inch to know if water is needed.
2.) Early on, place the pot in a sheltered site to protect from full sun and/or wind. (Do that today.)
3.) At this time, the only way to re-moisten the rootball may be to submerge it in water. If the potted plant is too heavy to do that, rig a slow primitive drip system of 3 or 4 plastic jugs, each with 2 pinholes in the bottom. Set on top of the rootball and fill with water daily.
Finally, unless this is a dwarf tree, it should eventually go into the ground.
But, if it must remain in a container, plan to re-pot it in 3 years, either into the same container or a larger one.