I have the same issue, after debugging, I realised that it was due to a memory crash in the callkit extension, from my logic, fixed it and the "Failed to request data for app. You may try enabling the extension again and if the problem persists contact the application developer." is gone. But now, I am seeing "An error occurred while attempting to enable app.", anyone got the same issue?

I spot the same issue, not sure what is that also. Do you have more logs? maybe we can determine ourselves