Thermostat connection problems with nest app

[Stressed]

I have nest app. 2 iPhones. One works perfectly and the other will not allow me to add any existing thermostats stating already connected.  Attempted to scan QR codes: no response. Attempted to manually add 6 character ID: no response.  Nothing works on wife’s phone. My phones works perfectly. 

[David_K · Accepted solution]

Once setup with the first phone, you don't use that method to add it to additional phones / share it with other family members. To share devices, invite their account/email address to the home:

Share a home and devices in the Google Home app - Google Nest Help

Note that even if the device only appears in the Nest app, you still need to use the Google Home app to manage home members.

The email address you invite must be a personal Gmail account, or if the person you’re inviting to the home uses another email provider, they must create a Google account using that email address. Once they receive and accept the invite, your device(s) will show up in their Nest or Google Home apps, as appropriate.

[Stressed]

David , thank you for your reply. After many hours scouring the internet, I read that going to a website would help and followed this websites advice, and after about 6-7 hours over a period of time searching for a solution as both apps stopped functioning on our iPhones  the same day in early January 2024, it worked for our problem and I was able to add my wife's cellphone back on as well as on my iPhone. Interesting that I overall spent almost and entire work day, and the solution took about 5 minutes once I found the correct reference. It just should have not been this difficult, IMO.