What’s on my leaves?

[BigLog]

One of my new hornbeams has developed some discoloration on the leaves. What is this and how do I get rid of it? It’s only on the new growth.

 

[Silentrunning]

Since it is new I am going to guess it is reacting to a change in environment - such as too much sun. Only the upper leaves seem affected. I would get it away from that wall and into some afternoon shade.