2015 Nissan Rogue - Looses power and struggles

while driving on the highway the carl looses power and struggles to regain power ,it is to be the cvt transmission?woulda transmission coolerhelp itand would itdiminishthetrade in value? after the car ccols downyoucanprocede

There are many possible answers for this kind of intermittent. It is entirely possible that it is NOT the transmission. A professional diagnosis is needed.
Throwing on an aftermarket device is probably the last thing you would want to do right now.

Just adding something like a transmission cooler will not solve this problem . I agree you need to have a shop look at this and I suspect your check engine light is on.