We just ran into this last week before running our Arrow x9. With the kart sitting on the ground turn the wheel lock to lock and see if both inside rear wheels get light. And see if the opposite front wheel has lifted slightly. Our Arrow had one side stay planted on the ground the other was lifting. We had full caster in at the time to perform check. What we had to do is bend down the front side corner to get it to plant the wheel properly. You have to support the good side front corner on a jackstand or floor jack. Have someone stand on the back axle/ wheels while holding onto the seat. Then someone can bounce carefully on the offending corner. It took us 3 tweaks and we had a kart that would jack on both sides equally. We figured this corner was tweaked from a slight corner shunt in Feb of this year.
PS I will try to find the link to a video I found that helped us Troubleshoot this problem…..