@Cru1 it isn't an error or a poor mapping algorithm.
It is the way the system is supposed to work.
The Airbnb search system is designed to just show the most relevant 300 listings to the guest.
To show all properties on the map would not work in many locations.
For example, Barcelona has over 18,000 listings. It would not work to pack all 18,000 listings onto one map. Even if they put them into pages of 18, there would be over 1,000 pages for the guest to read.
Hosts who want their listing to be more visible work to improve their search ranking.