Unable to add or remove external testers for Testflight

Repro steps

1. Go to App Store Connect
2. Tap on TestFlight
3. Under External Testing, Tap External Testers
4. It briefly looks like its going to show me the list of external testers.
5. The browser spins, and takes me to appstoreconnect.apple.com and the only options I see are the My Apps icon and the Users and Access icon.
6. If I click My Apps, I can tap on our app.

Taken back to our dashboard.

I've tried clearing cache and cookies, logging out and restarting my computer. It's been like this for about 3 weeks.

Affects both Safari and Chrome.