I created a custom peer population, and then created a test using it. When I run an instant test from the peer population to make sure my test can run fine, the test displays pending for more than 20 minutes. Whereas, when I run the instant test from a peer that I know is included in the peer population, it returns result in a couple of minutes.
Then about an hour later, I run the instant test from the peer population again. It runs right away.