XC90 T8 – Power loss electric motor

Hello! I have had my T8 (built in 2021) since September and during this time I had 2 times a noticeable power loss in pure mode, i.e. in pure electric drive. Both times it was a slope that can normally be driven without problems pure. Although I have climbed strongly on the accelerator pedal, the car has become slower and slower. 1x to a standstill, because I wanted to try what happened and the second time I finally started the burner by passing the gas pedal and solved the situation so. The first case was in September/October, so vmtl. somewhere at 15°C and yesterday it had about 0°C. Do you have an explanation or has someone like you already happened?