Connecting temp sensor to Nest thermostat

[Tickenigma]

I have two Nest Learning Thermostats; one upstairs and one downstairs. I bought a three pack of temp sensors and started to set them up. First one upstairs failed the connection test repeatedly. Tried another, same result no matter how close. Tried the the first one again downstairs, bam connected first try. Seems to be some issue with the thermostat upstairs but I haven’t seen how to troubleshoot that. 

[CoolingWizard]

@Tickenigma , did you check to see if the upstairs  Nest needs a software update to be able to support the temperature sensor? I am just guessing here since I have never seen this problem. 

[Tickenigma]

I’ll take a look and see. 

[Tickenigma]

It’s already up-to-date. 

[CoolingWizard · Accepted solution]

Hmm, it should be able to able to attach a Nest Remote Temperature Sensor then unless the BLE interface is defective. 

AC Cooling Wizard

[Tickenigma]

So, how can I tell if the BLE interface is defective? Is there a way to get it exchanged if so?