When you are sailing to wind with the rudder turned as far as it will go, and the boat responds by turning the opposite direction and into the wind, I call that "weather helm."
That is also what happens when the rudder stalls. I actually have almost never had that happen on either my 2010 AI (twist and stow rudder) or my 2015 TI but mostly see if with my big sailboat when I am trying to dock it. This usually happens at very low speeds and if you look at equation for lift from a foil (like you need from your rudder in order to turn), the lift force is a function of angle of attack and velocity square. When velocity gets very low, the rudder angle has to start increasing a lot to get necessary lift because "velocity square" is falling off so fast for low speeds. The high angle of attack causes the rudder to stall and lose lift and what is described in the quote happens.
To prevent this simply keep your speed up a little - which I do using the pedals and I think a really nice option to have.
To the OP, one time I went out without the rudder on my TI all the way down and had something similar to what you describe happen. Does your problem go away if you insure that the rudder is all the way down?