To reset the HomeKit configuration of the Smart AC Control V3+, you need to:
remove the device from the Apple Home app. Go to Rooms, select the accessory you want to remove, and scroll down to select Remove Accessory. Then, select Remove.
unplug the Smart AC Control, wait for one minute, and plug it back in to restart the device.
wait for at least an hour to give Homekit time to update.
set up the Smart AC Control V3+ with HomeKit again.