Hi, 

The yellow leaf blotches look consistent to a disease of apple trees ( which serviceberry is in the same family), called Marssonina Blotch.  This source does not say that it can effect Serviceberries as well but the symptoms seem to match.  It can be controlled with fungicide but in the instance for serviceberries, we would not recommend long term fungicide use. You can help control it by removing the leaves that are exhibiting the symptoms and also any fallen leaves at the end of the season so the fungal spores can be reduced from being over wintered. 

Another common problem of serviceberry are various rust diseases. Most don't overly effect the health of the trees though and control is generally not warranted. These are also caused by fungal spores.

Fungicides can have negative effects on our pollinator insects and long term use can disrupt the natural soil biome. They also need to be applied before symptoms show and then continuously per the label directions and until the weather conditions change to not have the spores reproduce. 

It looks like it could also be stressed from the location with the brick and pavement and drought and heat. Be sure to water as needed or at least once a week through the high temperatures and lack of sufficient rain. You can review our webpage on watering trees and shrubs for guidelines on appropriate watering. 

Let us know if you have further questions. 

Emily

That could definitely be it then. It may take it a little while to adjust to its new sunny environment.