Check the regulator arms they might be bent.Or one of the plastic slider wheels might have broken or need to be lubbed.
Also might be a weak motor.

It WILL NOT be a stretched cable because they don't have cables.
They use metal gears and arms.

 

yes i agree with mustang87 one og the guides must have moved its as simple as taking the panel off and actuating it to watch the movement as the window travels up a guide might be loose.

 

Ok. Its not the motor because thats new, so ill look at the guides.