Following A. Anquetil on the big foot hills route, the game incorrectly routes the player to a right turn at the bottom of the KOM decent
There IS a right turn at the bottom of the Zwift Hilly KOM (reverse) descent. That said, if you joined the Pace Partner from the drop-in screen, you do not need to concern yourself with turns, which will be automatically made for you. If you joined on the fly, you should get warning notices at the bottom of your screen (turn indicators) showing that the PP is going to turn, how that is different than your current route, giving you time to amend your errant course.
Or navigate directly to this (deleting the spaces):
zwifthacks.com/ app/ routes/ svg/ route/ ?world=1&route=41