Mapping toolbox, how to fix the coordinate frame when I zoom in/out?

Hi everyone,

I made a map with worldmap and I plotted inside some coastlines with geoshow. When I enlarge the map the coordinate frame enlarge itself and the map remains visible just in a rectangle inside it. How to avoid it? Is there a way to fix the the frame so that I can zoom in and out as I want?

I leave you an image to be clearer

[darova]

Can you show the code?