Q.My Newly Planted Loquat Tree (3 Ft Tall) Started Off Great Showing New Growth Which Now Appears To Be Shriveling & Dying. Why?
I actually planted 2 at the same time and conditions. Have treated them equal and the 2nd is still doing great and has grown about a foot.

Certified GKH Gardening Expert
Unfortunately, your photos did not come through. I am unable to see the damage. Because the other one is doing well, I would suspect that it is the luck of the draw.
Another thought is Fireblight. Erwinia is a brutal disease. Usually, this will infect all of the similar trees in the area. Maybe it hasn't started yet.
You can either treat it, or remove it and start over, with treatment in between. It can be tricky to treat.
These articles will help:
https://www.gardeningknowhow.com/edible/fruits/loquat/treat-fire-blight-in-loquat-trees.htm
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/edible/fruits/loquat/growing-loquat-fruit.htm