MATLAB: “surf” overwrites axis properties

axesMATLABplottingsurfview

I think I'm missing something simple here. I'm running this code:
fig = figure;
ax = axes('Parent',fig);
ax.DataAspectRatio = [1 1 1];
ax.XGrid = 'On';
ax.YGrid = 'On';
ax.ZGrid = 'On';
ylabel('y-axis');
zlabel('z-axis');
xlabel('x-axis');
view(3); % Here, the axes have equal aspect ratio and are labeled
[x, y, z] = sphere; 
surf(ax, x, y, z); % when this line executes, the aspect ratio changes and the labels disappear
As indicated in the comments, the "surf" command seems to be overriding my axis properties for some reason. If I check the axis object, the properties are still there (ie, calling ax.DataAspectRatio will show [1 1 1], but on the viewable plot, the aspect ratio changes).
Thanks.
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