Branch of letchi tree rotting and tree dying

[fuzz1]

Hi
I have two air layered letchi trees in soil. One died losing all it's leaves and rotting. The other starting to lose leaves from the tip and the branch rotting.

I wonder if anything can prevent the for. I don't think it's excess water

[Meat-Head]

Venomous poision in ground or air is as cold as ice?

[fuzz1]

Nothing like that I am in tropical country and the other trees grow nicely