Unable to activate after restore

The phone was ran over by a semi, and would freeze whenever you would try to unlock it with a passcode or face id. I have restored the phone to iOS 12.1 and now it says “Unable to reach activation server”. The phone does recognize the sim, and shows service, it just won’t activate. I have tried activating through iTunes, with no luck. 3uTools gets stuck for a few minutes on “Obtaining activation data”, then it says that it failed to activate. It is an AT&T phone, and we have already tried a new sim card. After swapping the boards out with another phone I have figured out that it is board level. What could be causing this in particular? I cannot see any damage to the board, however with the board being stacked, there could be damage that is not seen. Any help is appreciated.