MyInfinity thermostat dropping connection with Carrier server
Had the same issue with the Carrier thermostat shown in the picture.  Exact same symptoms - connected to the home network, but would not stay connected to the Carrier network, could not link to weather forecasts, etc. However, had an older Carrier thermostat upstairs (on the same network) and it was working fine. Noted that the DNS settings on the troublesome thermostat looked odd so compared with the DNS settings on the working thermostat.  They didn't match so I entered the settings from the working thermostat into the troublesome thermostat.  Waited about 15-20 minutes for the new DNS settings to propagate and now it is working fine.  Not sure how it lost the DNS settings in the first place nor why they didn't get reloaded properly.