Just indicating on AP also.cancels AP but not TACC
Here’s the rub: if you Originally set AP only, you actually set AP & TACC together and speed limit changes will take place automatically.
If you indicate or move the wheel taking control you shut off AP but not TACC.
When you re-engage AP whilst TACC is still operating, speed limit changes won’t alter the car’s speed any more.
To get auto speed change back, you have to cancel both and re-engage AP.