razer cortex problem plz help

i recently changed my resolution on fortnite from the booster prime section on the razer cortex program. i wanted to play streched and changed my resolution to 1680 1050(16:10) and now i cant go back to my native settings. whenever i start the game it stays the same with the streched res and 80 3d resolution. i tried everything but couldnt find any information about this. plz help just want to have a good experience on fortnite