The water temp sensors are the same on later UK TF as the Chinese TF (both water temp ECU and Water Gauge senders) The Chinese temperature gauge lights up one segment after another and three steady lights are 'normal' temperature.
Never seen that happen on mine but my best guess is it is in maybe some sort of test mode, or it is open circuit and it is searching for a signal. Cheapest thing to change is the blue water temperature transducer.
If you want to check the transducer is working it should give 3.25v @ 20c, 2.5v @ 50c and 1.15v @ 80c
By the way, many things on the Chinese MGTF that are different were actually designed by Rover before the collapse and sale to SAIC, the "new" dashboard was one of those things. Rover could not afford to implement them in Project Drive. It was designed to work with the existing sensors.
Cheers, Mark