I have the same issue persisting, stuck in subscribed state in testflight for seemingly weeks at this point. am logged into sandbox account with my real apple id. Feedback Assistant number: FB16534272 Thank you @App Store Connect Engineer

I have the same issue, which just appeared today. I made an appointment for a call with support, an automated call confirmed they would call me back in 15 minutes, at which time another automated call informed me that support is closed. I have not received any response via email yet. In the meantime I cannot create in-app purchases, etc. When I go to developer.apple -> Membership -> Show Agreements, it shows that I have accepted the Apple Developer Program License Agreement already. If you find any solution please share it here.