Dkozi

Sounds like it is a fungus or some other pathogin. Bahama Berry doesn't sound like it's from PA but fungus' and other organism's don't really care where the plants are from.

I would suggest removing the infected leaves from the tree and getting them out of the area that the tree is in. If you have a local arboretum or university around you can try keeping the leaves in a zip lock baggy and seeing if there is an entomologist who might be able to diagnos what the problem is. If you use pruning shears to remove the leaves then sterilize them after words with rubbing alcohol.

When temperatures are right for your tree it will probably benefit from being outside. Most trees are not in any harm if they are growing vigorously and are generally healthy to start with. It is usually when two or more infestations are working against a tree that it is most vulnerable.

Good luck. -Dkozi