Cooling system

I replaced the temperature sensor with new one's and used a scan tool to read the sensor temperature. The reading is the same i.E Red lamp on at 94 degree c instead of 120 degree c.

I have a Hyundai new accent 2008 car, 1.6 l, 4cyl, fwd, manual 1.6l, 135000 km,
Because of overheating before, an over hole maintenance was taken and due to a little deformation in cylinder head, 2 head gasket are installed to compensate the cylinder head thickness after resurface it
The cooling system have 2 indicator lamps one blue for low temp. And the other red for high temp. After some weeks I found the red lamp on in traffic but didn’t in highways
By checking the cooling system
� Replacing thermostat, temperature sensor, radiator cap,
� Cleaning radiator (aluminum type) internally and externally, checking the coolant level regularly is detect no leaks
� Checking the electric fans operation are ok.
� Checking water pump impeller is ok.
� Checking by using another controller
� Checking by using instrument cluster and indicator lights panel controller
� Checking bad gasket and cracked head using block tester and test fluid it found ok.
After that I found the same state red lamp on in traffic but didn’t in highways
Using scan tool which indicate that red lamp is on at 94-96 degree c and radiator fan on at 96-98 degree c and code p0118 ( mean engine coolant temp. Circuit high input) so why red lamp