Hello,
As indicated in the FAQ, and written repeatedly on the forum.
During the race, your courses may change, but the server will smooth it only every 4 hours on your screen.
This explains the passage through the land of some boats, the smoothing is to record a track point every 4 hours and then draw a line between these 2 points and so on.
Throughout your journey, it is not the smoothing, which is taken into account, but your real trace, this is why some of you feel they have validated a buoy but it doesn't get green, or that others pass through the land.
Best regards,