2017 Taco Heater control temp not working

Hi all, I have a 2017 Taco V6 TRD and the issue is when the temp is at Low it works fine but if I change the temp just one degree up on either the passenger or driver side controller, the temp gets fully hot. Not sure what the issue is; controller or the heater valve. Any help will be appreciated.

 

I'd want to go into the HVAC module with an appropriate scan tool and verify all the temp sensors are reading properly particularly the interior and ambient temp sensors.