RELEASE build error: module "ResearchKit" not found

[ghost]

When running the project in DEBUG the project builds with ResearchKit fine. When trying to release a TestFlight build, or when building in RELEASE the Xcode project can not find the module "ResearchKit". It seems, something in Xcode (the build system) is preventing the Project module from accessing the ResearchKit module in Release config.

Thought maybe the lack of the bridge header file/path was the problem, but after adding a bridge-header file the project was still unable to find the ResearchKit module.