Okay, so I was able to resolve this issue and am posting here in case anyone else comes across this post.
I had to select the Spline, click on the Devices tab, and make sure I had the ‘Looping Track’ enabled.
My track is looping, but I hadn’t set it to work that way. There’s a ramp where I didn’t connect it to the next spline point. When I enabled ‘Looping Track’, it automatically connected those two points. I just had to select the spline and set the road type to None so that I could still get the ramp I wanted.
I think the reason why I got the Missed Checkpoint at that spot is based on the number of each spline point. It just so happened to be between the last and first spline points–even though it wasn’t at the beginning/end of the track.
Anyway, I hope this helps someone!
