Again, I will reiterate: the turn signal is *not* supposed to disengage. The current manual explicitly states as such. See below, emphasis mine:
Cooperative lane changing
To change lanes without disengaging or deactivating Highway Assist, activate the turn signal in the direction you will be changing lanes. See
Turn Signals.
When you turn on the turn signal and turn the steering wheel, Highway Assist will be temporarily overridden, allowing you to manually complete the lane change. When the vehicle is centered in the new lane and both lane lines are detected, Highway Assist will automatically resume.
When you turn on the turn signal and turn the steering wheel in the direction of the intended lane change:
- The Highway Assist indicator will gray out
- The lane will not be highlighted