Turns out the default tests created by Xcode are actually UITests. Creating a brand new test target fixed this.

I’m curious about this as well. Would love the ability to read a user’s Guides.

I just requested a session with Developer Technical Support via Apple's new Tech Talks 2021 program. I'd recommend others do the same. Hopefully we'll be able to get some sort of acknowledgement, or the bug actually escalated and looked into.