I drove one of these cars (Dodge Caliper) with the same transmission and it is different. While you think it is slipping due to the reving motor it is really working as designed. Watch the tach and the speedo and if the speed of the car is increasing and the tach is staying at the same rpm 3,500-4,000 rpm then the car is working properly. If the motor is reving and the speed is not increasing then you have a transmission problem.
The CVT transmissions in these cars isn’t that robust so it is hard to tell if you have a problem or if you are just not used to the feel of a CVT transmission.