title: iOS TestFlight: Internal Tester not receiving invite
body: <p>I set up a build and add two Internal Testers. Immediately after pressing the "Invite" button I noticed that the checkbox next to my email address was the only one that remained checked. The checkbox next to the second tester was unchecked. So I clicked the checkbox and sent another invite, but the same thing happened. I thought nothing of it, figuring it would become checked when he actually installed and tested the app. But he says he never received an invite. Does anyone know if I'm doing anything wrong?</p>
  
  <p><img src="https://i.stack.imgur.com/EPZgT.gif" alt="enter image description here"></p>