Check to see if in your settings you have apps to automatically update. Turn it off and manually update your apps thru the App Store. Make sure that the tvOS beta 12 is properly installed and trusted. Look at your iPhone storage to delete any iOS update downloads. Shut off your phone and re-start it and you should be good to go. One other thing you might want to try is to sign out of iCloud completely, shutdown, restart, and log back in.
P.S. - This is BEFORE you jailbreak.
Been there, done that.