There seems to be an issue with the formula used to say whether a dot in land or not.
If you look at Africa there is always a vertical line of uncolored dots - see screenshots . I have tried lots of variation in the playground but could not find any parameter that solved it. I also noticed a small glitch for Antartica and was wondering if it was the same issue

It might be linked to precisions as I don't see it in one of your post picture : https://pbs.twimg.com/media/FGa7EGPXEAUF0bd?format=jpg&name=large

PS: Could it be a PC/mac issue as I looked at our project on a mac and couldn't replicate the error.