I have a longan tree in a pot. I have had it for a few years, but I cannot get it to keep it's leaves and branches. The meristem keeps making baby branches. When they mature, the leaves begin to brown on the edges. Then, over time, the whole leaf browns and the branch falls off. Right now it is about 2.5 feet, but only branches are near the meristems.

The multimeter readings show the pH is close to 7 and a relatively good dampness.

I have tried:
More light
Less light
Spraying leaves to increase the humidity
Transplanting
Adding pellet fertilizer.

Nothing works.

I have never really heard of anyone having great success growing Longan in a container in the house. Even outdoors in a relatively frost free climate they eventually have to be planted into the ground