So before the Hot Wheels expansion was released, I made it my goal to 100% the main game of Horizon 3. I managed to reach 99%, with the missing 1% coming from not doing enough of Horizon Promo.
However, once I downloaded the Hot Wheel expansion, I noticed that not only did my percentage go down, the game is saying that I didn’t do all danger sign jumps and drift zones, despite the fact all of them having 3 stars on my map.
Its a known issue. I also had 100% completion on the main game but after a forzathon one day it started showing only 94% completion. Now around a month later it says 97% completed. Redoing some of the pr stuns may help to bring it back up but i can not guarantee. Personally i just live with it, as long i know that i done everything im satisfied
*btw comparing your stats to mine it shows for me drift the drift zones only 7/17 completed and danger signs 6/16. I also have 3 stars on all