My Catalpa looks about the same here near minneapolis. it was sold as a northern catalpa but turned out to be southern catalpa. Not sure why if finally succumbed this year because it wasn’t that cold. It made it through several polar vortices with just some minor tip dieback but the trunk did crack one year.

Over-watered and/or over-fertilized is a potentiality no one could argue against, given what's known, which really isn't a whole bunch at this point. How about an image of the entire planting, including the pot? The usual suspects would be: Over/under-watering, root congestion, a high EC/TDS level (too much salt in the grow medium/ soil solution), a badly skewed nutrient ratio in the grow medium due to the soil not being flushed regularly or effectively, natural senescence - depending on where the spoiled foliage is located on the plant. Sometimes a valid diagnosis can be reached by the process of elimination. Other times, you might find it easier to simply take a good overview of all cultural conditions you hold sway over and make your best attempt to dial them into the plant's sweet spot. Al

Something caustic was used in the way of a cleaner or somehing whether they wll admit it or not. I do not think you will be able to get the finish back, they are etched permanently most likely.

I'm not sure when this happened, but it has two branches, and the leaves on each look very different from the other. Is this common? An inexplicable aberration?