Ours was doing exactly that. It would randomly change temp no matter
what we tried. I posted our solution to help anyone with that issue.
Don’t dismiss this if you haven’t looked into it thoroughly. I hope this
helps someone out there. Trust me, you ...
We did. Just go into your settings via web browser and find Calendar.
Nest “learns” certain temps and schedules these changes in temperature
at random time that make no sense. But you can delete them and then
disable this feature while your in there....
This needs more attention on this page. This is the only thing that
worked for us and seems to be to fix. Thanks so much for posting this
idea. It wasn’t very difficult to find the schedules that needed
changing using your laptop.