Hello Frederik!
The measuring quest, is adapted for each character so that's why noone find the Points of Interesting on same place.
If you dont have access to that place on the map it will show the name "Grey" instead of White:
For example I'm Blue Djinn, thats why the Green Djinn place looks grey on my map:

This situation also happens in Cormaya, Gray Island and all those places that are open only during events or special dates.

So you just have to walk all around and check again cuz for sure there is a little point you are missing.
As a tip I recommend you download the map from Tibia Maps "without markers" you will have all map but it will shows a bit "shading" at the parts that you haven't walk, so there is a good way to know what place exactly are you missing.
Good Luck on your search!