3D scatter + 3D regression plane

coding newbie here - I copied the general outline layed out at 3D scatter + 3D regression line. I have 11 uniqe x values and 3 unique y values, and when I make the surface it only plots 9 points making a 3x3 surface which excludes most of the x values, so the plane spans the whole of the y but only part of the x

this is what my matrix looks like

       [,1]       [,2]      [,3]

[1,] 0.5003214 0.38398479 0.4421531
[2,] 0.2736258 0.15728919 0.2154575
[3,] 0.3869736 0.27063699 0.3288053
[4,] 0.6136692 0.49733259 0.5555009
[5,] 0.3416345 0.22529787 0.2834662
[6,] 0.2282867 0.11195007 0.1701184
[7,] 0.1602780 0.04394138 0.1021097
[8,] 0.9763821 0.86004555 0.9182138
[9,] 1.0217213 0.90538467 0.9635530
[10,] 0.8403648 0.72402819 0.7821965
[11,] 1.0443908 0.92805423 0.9862225

any ideas of how to have the surface cover the whole extent of the data?