WiFi Thermostats ME81H 16A Failing After One Year - Display Issues

Hello, I have a problem with smart wifi thermostats Model: ME81H, 16A. I have installed 8 of these thermostats a year and a half ago, everything worked until now without any problems, until suddenly they started to fail one by one, they get power but apart from displaying the lower signs for the settings, nothing else lights up. I have a question; does anyone have such thermostats and a similar problem and what could be the reason and how can it be corrected.

I enclose photos of the thermostats,

Does each thermostat have its own independent power supply, because if they are all powered from the same power supply, it is possible that the power supply is inducing something and damaging them ?

Each thermostat is in a different room and has its own power supply

Hello

I own 2 pieces and they have a factory defect the path supplying the relay contacts and the N output is too narrow and heats up very much, thus other components also.

I supply power to an underfloor heating system with a consumption of 16A and in my case the relay is damaged, but other components can also fly from the temperature.

It must be immediately thickened with tin or soldered a piece of copper

Note that they have been withdrawn from Ali