Bug Body of UnityTest method does not always execute when using SetUp method to EnterPlayMode

I think I've discovered what appears to me to be a bug with the EditMode Unity Test Runner. I've reported it to Unity via Help > Report a Bug, but yet to to receive a confirmation. I thought I'd share it on the forum in case anyone wants to try and reproduce it, suggest a workaround, or point out anything I've missed.

Here's my original report:

I've attached a package containing the test scripts I used.