Why is my VentGrid temperature reading different than my probe reading?

Why is my VentGrid temperature reading different than my probe reading?

Do you have a minimum ventilation rate greater than 0%? If you have your ventilation running from something higher than 0% to 100%, that will cause the VentGrid to add to the vent rate because the minimum is 25% and not 0%. The VentGrid will show the temperature reading as what is operating at (actual temp + increased vent rate because of settings), rather than the actual temperature.