For some odd reason the achievements doesn’t seem increase the ride counter if you don’t enter the coaster carts before it leaves the drop off point.
Which means if it’s parked right in front of the stop lights and you get in at that point, then you won’t get progress for that one ride and you will need to either sit through an entire ride before you will actually gain progress, or you can enter the carts while they are entering the drop off section at the end of the ride.
If that doesn’t work you can try checking if you don’t already somehow have attained it on steam
https://steamcommunity.com/id/YourSteamIDOrNameHere/stats/394690/achievements/