Google Nest Community

Still having problems with the thermostats. Says that they are off line and I have to manually switch them on and off. I’ve read that some routers are not compatible with the thermostats. Any help appreciated

I have 2 nest thermostats installed in the house. Up until a few months ago everything worked well but then just after I changed my internet provider the thermostat’s went off line. I had the man down who had installed the system but he couldn’t work...