Allion 260 -2011 Problem when accelerate at the engine cool condition

[Cha1990]

My car recently get an issue once i start the car after 8,9 hours. (When engine is cold)

I can start the car normally without any issue and at the N,P gears when i push the accelerator RPM goes up and no any issue can identify. 

But when i change the gear to D and when i push the accelerator RPM does not go more than 2000 and car can not pickup a hill. But after few min it comes back to normal and car runs perfectly. no jerks no gear engagement issues or vibrations can be identified. 

To check above problem on a flat road, i stopped the car on a flat road and kept two wood bars to wheels and redo the above steps to check what happen. same issue was there. Car can accelerate on P &  N Gears,  when i change the gear to D and when i push the accelerator RPM does not go more than 2000 and car can not move up from the wood piece But after few min car come back to normal.

Mileage 85000KM & 80000KM service done at TL 

Spark Plugs not changed/Air Filter changed/CVT changed at TL

 

Any suggestions?