Configuring Mapping Rules - Product v Backend

I'm hoping to hear from 3scale Community members about their experiences setting up Mapping Rules after the Aug 17, 2020 update to the SaaS-based Admin Portal.

When Red Hat redesigned API Services into separate Product and Backend components, they included an option to create/invoke Mapping Rules from either component - or both.

Since that change, I have been UNABLE to create a successful API Service with Mapping Rules - whether using the option in either Product or Backend. My cURL statements continue to return "No Mapping Rule Matched".

I found that my API Services created PRIOR to the 8/17/2020 change were automatically separated into Products and Backends as part of Red Hat's upgrade conversion process. In those examples, the Mapping Rules defaulted to the Product option. Those API Services, both before and after the conversion, are working fine.

Using those API Services as my post-change 'template', I configure Mapping Rules for my new API Services to match them exactly. But I still cannot get my new API Services with Mapping Rules to work.

My latest API Services 'without' Mapping Rules work fine.

I have been working with Red Hat Support since early September 2020 on this issue. I am very anxious to hear from others using the 3scale SaaS-based Admin portal.