Plot triangular mesh with m_map toolbox

I have a problem when i'm plotting triangular mesh with trisurf and m_map toolbox.

    m_proj('mercator','longitudes',[xmin xmax],'latitudes',[ymin ymax]);
    trisurf(TRI,XX,YY,Hs,'EdgeColor','none');
    m_grid('box','fancy','xtick',xmin:deltax:xmax,'ytick',ymin:deltay:ymax,'tickdir','in','fontsize',10);

In the first and second line i don´t have problem (figure 1), but in third the plot reduced considerably size (figure 2), attached plots's

In advance thank you

[Kelly Kearney]

What are your values of xmin, xmax, ymin, and ymax? And what are the ranges of XX and YY?