Issue with Controller Response in DWSIM Refrigeration Cycle Simulation

[Hugo-15]

I am trying to simulate a simple refrigeration cycle. I added a controller to adjust the refrigerant mass flow rate based on the evaporator duty. At first, the controller seems to work properly.
However, when I increase the evaporator duty, the refrigerant mass flow rate remains unchanged. I also performed a sensitivity analysis with the following setup:
Independent variable: Evaporator duty
Dependent variable: Refrigerant mass flow rate

Unfortunately, the sensitivity results do not show the expected trend, and the mass flow does not respond to changes in duty.