I had the same issue, caused by changing the Date & Time settings from automatic. ✅ Setting it back to automatic solved the issue.

The same issue occured on our side starting with 01-08-2024. After a lot of investigation, it turned out that Apple changed a leaf certificate in TestFlight, so it caused to our app to crash because of a 3rd party dependency did not include that certificate. In our case it was Promon Shield (https://promon.co/dev-updates) Hope that helps.