LQI Has Problem With Discrete Plant

Hello,

I am attempting to use lqi() for a reference tracking application with a discrete-time plant. When I run lqi() it fails to stabalize the plant except for a very particular choice of Q which then gives me the warning "Solution may be inaccurate due to poor scaling or eigenvalues near the stability boundary". What is so surprising to me is that dlqr() is able to stabalize the plant not problem for simlar values of Q and R. Is there any procedure that will allow me to stabalize this plant without randomly guessing Q's and how can I avoid issue like this in the future?

Thank you!