Error trying to test StoreKit in someone else's app.

I'm an Apple developer but I'm currently trying to test someone else's app that uses StoreKit for in-app purchases. The app is being tested using TestFlight.

When I run the app, I always get a StoreKit error. On the screen, I see:

"App Store communication failure, please try later"
(with a close button to dismiss it)

In the app's console I see:

"StoreKit: Unable to Complete Request"

This happens with 3 different apps that the company is currently testing. No one else that is testing is getting this issue. StoreKit is working fine for them.

I suspect the problem has to do with the fact that I'm an Apple Developer as well. There must be something about my account that is tripping up StoreKit. I don't currently have any Sandbox test accounts. None of my apps are currently in testing.

Anyone have any thoughts?

I did capture a log from the Console App, filtering on StoreKit:

If you search the log for my email address "bill at otherwise dot com" you will see some errors that may mean something to someone.