Ring doorbell elite no power

Recently our doorbell just goes offline and randomly recovers. When offline I have removed the fron fascia plate to reset it (15 seconds on the little button) but it does nothing.
I have tried power from both the PoE adapter that some with it and also from the switch that normally powers it and a few other cameras.
The wall it is installed on in South facing so I wonder if its the heat, but either way it should work.