Power, speed & resistance gone crazy

Hi anyone had the situation where riding London loop suddenly the resistance comes on then drops off and the speed is up to 10kmh over what it should be all happening whilst on 0% grade. All after asked to upgrade Zwift app on Apple TV?

I experienced this yesterday. My trainer presented less resistance climbing the Titan KOM than when I descended the other side. My cadence stayed the same and I was not shifting. I had settled into a groove then the trainer would offer almost no resistance on the hill then spike very high. Once I started descending I had to work really hard and put out twice as many watts to go downhill. ATV/SarisH3 connected directly over Bluetooth. Trainer was selected as controllable. No one else home so no other wifi or appliances running in the house.