Possibility that the cross shaft adjustment is simply too tight. At dead center (the "high spot"), there is normally more torque required - this should be the zero lash, straight-ahead point. If it wasn't centered when the adjustment was made...and the person who did the toe-in adjustment was sloppy or lazy...

Try backing it off a half-turn just for giggles.

A pretty close adjustment can me made, BTW, in the car. Ask after you see the result of the above.

Rick