Simulink models typically run to completion each time they are invoked, so connecting them up for there to be a "live" connection is not typically going to work.
You can, however, get it to work if you form a udp or tcp connection between the MATLAB level and the Simulink level.
You might want to instead use simulink to implement the controls; see https://www.mathworks.com/help/simulink/dashboard.html
