HELP. Can't seem to turn my rover.

The rover I made recently can't seem to turn. The only thing that it does is skid sideways slightly when I try to turn. Everything else works fine, it travels pretty fast and it breaks well. I tried everything from rebuilding it, changing wheel size , adjusting the grip and torque. Still don't work. Here's the link to the rover. https://www.simplerockets.com/c/6q8hV0/Scarab-Rover-help