Thanks for the question. 
Could you please send us pictures of these white areas from both trees?  Label the pictures as to what tree they are from. Try to include some close ups. It is nearly impossible to provide you an intelligent answer in the absence of this information. 

Many thanks. 

Thanks for getting back to us with pictures.

Bottom line is that I do not believe that there is anything wrong with your tree. It looks healthy and has good foliage. I think that the white spots simply reflect lichen growth. I suspect that this is also the cause of the white spots on the other trees in your neighborhood.

Lichens are actually two or more organisms growing together as a single, stable unit. It consists of one or more species of fungi and one or more species of bacteria. The bacteria provide nourishment to the fungi, and the fungi provide an environment on which the algae can grow. The color of lichens can vary considerably depending upon the types of bacteria and fungi present.

Especially when the weather is hot humid, lichens often form on the bark of trees. No harm to the tree occurs, other than cosmetic, and they do not have to be removed. See:

https://www.gardeningknowhow.com/ornamental/fungus-lichen/treatment-tree-lichen.htm - :~:text=Lichens on trees are a,sun, which feeds the fungus.

https://www.independenttree.com/is-lichen-on-trees-harmful/

Thanks again for your question.

Glad to have been of assistance.