With the ONE V5 case the fan is controlled by kernel, not by argononed via I2C. If you want to set the behaviour manually you could play a little bit with that:
cat /sys/class/thermal/cooling_device0/cur_state
echo "4" | sudo tee /sys/class/thermal/cooling_device0/cur_state
For more information please read: Argon V3 fan speed issues - #10 by HarryH