When exiting from the Buckingham Hairpin on the London map, RoboPacers take a sudden acceleration and drop the group. This is a consistent behavior and happens every lap, with different RoboPacers and different routes and has for a long time.
Before entering the hairpin, the group is keeping pace:
After exiting the hairpin, the RoboPacer accelerates and forces the group to go all in to catch up:
There is a slight gradient change from +1% to -1%, but that doesn’t feel like it should have this big of an impact. I don’t recall encountering a similar situation anywhere in the game world.