From rolling back, this is a malfunction.
There could be two faults.
1) Low oil pressure.
A) the Wear of the oil pump.
B) the Oil loses its properties.
C) high oil temperature, it becomes too liquid.
2)Wear of clutches in the packs. Clutches become thinner and can't hold the weight of the car.
The first thing I will recommend you. Replace oil. To set the correct oil level.