I would check the amount of water provided and /or drainage.

Omar

Thanks for the response, and water and drainage might be an issue BUT the leaves are bumpy. Not smooth but with raised areas and disclorations. The pots have drainage holes, I see water coming out the bottom when I do water them. I have a moisture meter I use and keep them on the dry side. I don't see any mites, flies or sticky residue from pests. The new leaves are looking deformed with small irregularities.

Anyone else have suggestions?

I live in Katy and one of my mandevillas is also showing the same symptoms. I think they are prone to fungal disease especially when the leaves stay wet at night. I'm sure all the rain we have had has contributed to this problem. I plan on spraying with a fungicide to see if I can correct the problem.

Here's something I found on the web. It's vague and general but it's still a good check list.

Omar

Have you tried your water meter ALL THE WAY to the bottom? i’ve found that some pots either are not completely draining (clogged with dirt) - but it right at the plant’s feet; or you see them drain but they are so dry or rootbound the water drains through the sides, and out the holes, completely bypassing the plants drainage system.