I'm getting reports that after downloading my app users try to open it and are getting a blue screen that says "App Unavailable Please contact the site administrator for more information." I'll attach a video and a pic. I can't find any information on this. Can anyone help?

I've been using TestFlight with my app for weeks. I just uploaded a new update to App Store Connect and got the email that the new version is available for TestFlight. I open TestFlight and can see the new version of the app with "Update" next to it. At first, I got an error that said "Beta Expired". Now, test flight says "Install" next to the app and it if pressed it runs like it installing, but nothing happens, it then returns to the "Install" status. I've tried removing and re-inviting the user, delete and reinstall the app from app store, and deleting and reinstalling TestFlight. Nothing works. Can anyone help?