Were you able to figure this out? I'm running into this exact issue. I've been able to find a partial workaround because I have the following scenario:
I created individual survey forms for each of my two tables & feature service in Survey123 Connect.
Agencies (parent)
Programs (child to Agencies, 1:M)
Services (child to Programs, 1:M) - this is the layer with location geometry, and the other two are tables
I cannot access the parent data using a feature report template run on the Services, it gives me the same error. However, I was able to run a similar report on the Agencies, and access the programs and services. It didn't work exactly, because I was unable to filter conditionally using any of the child features, only the parent.