Nest thermostat always says offline.

[cleandog]

I have a nest thermostat and used to be able to control it with iphone. Months ago I lost the ability to control my Nest thermostat using my iphone. Now it always says offline. I have done everything Nest suggests to remedy this problem and nothing I have ever tried works. 
Nothing seems to work.

Trust me I have tried it all, many times. 

I have internet and wifi connection. I have restarted both.

I have removed and reset thermostat connection.

I have removed app from iphone and reinstalled it.

I can't find a number to call Nest support.

Can someone help me?

i am stumped 

thank you,

Joe

[Hameed]

I have the same issue with a pixel phone.

The thermostats/nest pro works fine and the utility company can put it in rush hour remotely but I can't do much it from my nest app as it shows most of the time as offline. I kept playing and rebooting etc. but it doesn't solve it too. 

Any suggestions would be welcome, what can be done?!