Yes, today i received an e-mail by the Apple Support Team, they were able to solve the problem. To speed up the process, you can send a video proof of what is happening, with the Beta Contract is missing from the dev tools of the browser. Ask them to forward the issue the Apple Engineering Team, they will ask for a Senior Advisor to look into your case and then he will forward the case to the Engineering Team. Now the problem is solved. It required exactly one week in my case. 21 April 2022.

Here to say that i am still receiving the error "Beta contract is missing for the app" even if the Engineering Team is trying to fix the issue. Every five days they tell me that the issue should be resolved, then i can approve some builds, then the issue happen again. Today, 3 May 2022 i still got the same issue and i am still in contact with the Senion Advisor for a ticket i opened three weeks ago...