I have a Jaboticaba bonsai indoors live (we live in Massachusetts).

It should be outdoors all summer.

It was repotted last summer.

In what?

The problem is that many of the leaves are dropping off. The older leaves
seem to brown at the tips, then drop,

That usually indicates poor drainage, excess salts, or some other problem at
the roots.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)