...my off-the-cuff guess would be soil is too wet. Stick your finger in about 2 inches from the trunk
and see what you see. Where do you keep this plant? How often do you water. Been fertilizing
at all? With this great weather we're having now I hope you are keeping it outside and letting it
get some sun. What kind of soil is it?
Need more info and your caring instructions to better get a picture....
We can fix this (I think)
Gary