Learning thermostat won't upgrade & can't add sensor

[itazzz]

I have a 3rd Gen nest learning thermostat. There's not wifi issues, it's connected to internet. It hasn't updated firmware since Nov 2021. It's running firmware 5.9.5-2. I recently purchased nest sensors, but when I try to add them, I got a software update needed error. When check for updates on the thermostat it says it's up to date, but I think there's newer firmware. How can I update the firmware? 

[David_K · Accepted solution]

What country are you located in? 

[itazzz]

I'm in the US, and I have the north American thermostat (with the wires and the blue water balance thing) , but for some reason it has the EU/UK software. I called Nest support but they couldn't help. 

[David_K]

Where did you buy it from? It running EU/UK software is the reason this isn't working for you.