Report advice : Activities in Change Notice, Change Task & Change activity

Hello all, 

I am currently working on a complex Report for ECR system. I have made a great progress by studying other threads and also found some QML´s. However I am now stuck in and I would need your advice. 

I was able to create a report able to track data in ECR, ECN + DT and examine complexity, how long it took (by calculation), etc.

My trouble is to track activities in different objects. I was able to create a connection Change Activity → (Primary Business Object) → WORK ITEM → (Source) → WF Assigned Activity, that will report activities I needed however only for one of the Objects, but when I connect WORK ITEM with (Primary Business Object) to any other Object (ECN, ECR) I get no results. 

Can you advice what should I to to get activities from all of the types in single report? 

Thank you in advance.