Problem in plotting o sign

Hello for every one I have a problem regarding with o symbol.

X=rand(100,1); Y=2-X

plot(X,Y,'ro') Here I can see only square figure and couldn't see my points. However, when I change the code as below plot(X,Y,'rd') I can see my data points

the issue is also happened when I use scater It is important to mention that I use Marlab 2017 Please help me to address this problems

Regards