The trims are basically a rocker that pushes on a couple of micro switches, it sounds like there maybe something stuck under the rocker that is pushing on the left trim micro switch.
Note I've had my Profi for over 5 years and it's used all year round, all the logos on the buttons are worn off but it continues to work faultlessly. You could try blowing on the trim switch and seeing if that clears the problem, but maybe best to send it for a service. Where are you?