I saved my Madagascar palm trees 3 years ago from Near Death out of a plant Salvage bin they have always been very healthy and have grown from 5 in to 3 ft lately they have developed yellow spotting about 2 to 4 in in diameter the leaves are green healthy and flourishing it\\\\\\\\\\\\\\\'s just the yellow spots on the palm itself.
It does appear to have contracted an infection. I would treat with wettable sulfur, since it will acidify the soil while killing the disease. These succulents will be very sensitive to overwatering, so be sure that it does dry out well between.
Other fungicides may be used, but may not serve the same purposes as sulfur, which can be used in lime form as well.
https://www.gardeningknowhow.com/plant-problems/disease/using-lime-sulfur-in-gardens.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/side-dressing-with-sulfur.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/sulfur-in-plants.htm
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/houseplants/madagascar-palm/madagascar-palm-care.htm
My palm got too much water in a recent rain storm. It has bent over at the skinny part of the trunk. Can I do anything to save it?
If this is in container, then repot into a container with plenty of drainage holes to allow all extra water out, then you can prune it at the bend. It will grow new shoots to replace the top.
If this is in ground, then prune it at the bend. Pruning carries quite a risk, but less than leaving the branch to get infected, further.
Apply a fungicide and wait for new growth.
https://www.gardeningknowhow.com/houseplants/madagascar-palm
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm