Termometre does not report temperature anymore

After 2 years of good workind my wifi tuya termometrer are unavailable. What is the best way to make them work again.

I notice that the rpi do not have access to the wan any more. then that the ip adress were strange like 172.x.x.x. I think that it was good time to test the backup. so I decide to make a fresh install and reload the backup but fresh install do not work. I will make a new post

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