How to plot Smith chart
It looks like the values you gave for rho are all real numbers.
And it looks like Matlab plotted some values along the real axis:

If you want to get a result like your other example, you should provide complex values of the reflection coefficient, not just the magnitude or real part.
If you were simulating the reflection of a purely resistive load on a lossless transmission line, then real-valued reflection coefficients are what you should expect, and you may already have a correct Smith chart.