Approximately every other ride the bell starts to ring repeatedly without any input, sometimes several times on the same ride. I have disabled the Di2 button that was previously programmed to actuate the bell and made sure that nothing was dripping on (sweat) or touching (dirt, debris, finger) the screen. It does not appear to be related to vibration as it occurs on very smooth roads (as well as on gravel). The ringing continues until I touch the screen several times. I am running the latest firmware (29.22). Thoughts?