ok Dan thank you problem resolved here and my fault.a new Hytron cable
modem had been installed - i turned the firewall to maximum security and
that caused the issues with nest thermostats and camera for 36 hours.
have now edited the firewall setting...
all 4 of my 3rd gen stats offline on app but working fine in wall and
have IP addresses on router, looks like app issue. Same for my outdoor
cam - works fine on google home on chrome browser but offline on app....
