I also have a potted banana plant it is a pup about 3 feet tall in a 15 gallon container, my neighbor has a plant and a pup grew up on my side of the fence. I would have left it in the ground but its base was about to tear down the fence in a few months if it wasn't moved. My leaves are doing the same thing I think because it is so hot and dry where I am 95-100 degree average in the summer. I too am searching for a few tips to rejuvenate it. I have it in partial shade although it has been potted for the last 2 days.

may get some answers from www.bananas.org I have gotten a lot of info there

Took mine out of the pot put it in the ground and it has taken off much better than it was in the pot.