Is there any chance a herbicide (you or a neighbor) could have been used... near enough to the trees for herbicide drift to have occurred? Or has a "weed and feed" type of a product been used on the lawn near the plant? It really has the appearance of herbicide damage but I have not seen it like this before.
If you really would like to rule out pathogens such as the bacterium that causes galls on Oleanders, Loropetalums and Olives, you could send a sample to a Plant Pathology Lab for testing, like the Texas A&M Plant Disease and Diagnostic Lab:
https://plantclinic.tamu.edu/f...
Check on the possibility of herbicide damage and let me know what you find.
