Ssangyong Korando in the snow, drift session

Somewhere in the far west of Romania

SsangYong Korando Style+
1.5 tGDI, AT AWD
Tires: 235/55/r18 Dunlop Sport AllSeason

At the time of filming there was about 10 cm of fresh snow on relatively dry ground. Ambient temperature +3 degrees.
AWD and AT - enabled, ESP - disabled.
After the session, going out on the asphalt, I noticed a rhythmic knocking in all the wheels, but the phenomenon disappeared immediately after I washed the car. From this I conclude that it was due to the accumulation of dirt and snow.
The next day I repeated the session, at the same temperature but on a slightly softer ground and about 20 cm of snow.
After about two minutes the "4WD Check" came on and I no longer had four wheel drive. Everything was back to normal after two or three minutes. I conclude that the system has overheated due to the higher snowpack and softer terrain.
When returning to the asphalt I again noticed "rhythmic vibrations" in the wheels, they disappeared after washing the car.