I can’t just plot the X-axis with strings and expect the Matlab plot function to do what it is supposed to do (Which is label each X point with the string). The work around for this inconvenience is to use the XTick and XTickLabel. Found this useful stack overflow article that explains it all :)

x = 1:5;
y = rand(size(x));
plot(x, y, 'b')
set(gca, 'XTick',1:5, 'XTickLabel',{'A' 'B' 'C' 'D' 'E'})

Use the XTick to signal how many X axis elements there are. And use XTickLabel to signal the labels for each X axis element. In my case I only used XTickLabel.