I don’t have the user photo set in AD or share-point. Test SFB client looks like below before adding the photo.

This blog is just for reference. Most of the steps are same as Lync 2013/2015. My CMS database is located in SFB 2015 pool. CMS replication is uptodate.

This is just for awareness, I have a SFB 2015 deployment on Hyper V with limited memory. My SFB users are assigned with address book web search policy. When you have high memory utilization, address book search may not return anything while searching for a keyword.