Having found this answer suggested in other postings without a clear indication of success, I thought I would post my experience here. I installed my first Wyze thermometer and was unable to pair it with my Android phone (Samsung S10). I was frustrated by the advice to try another phone and particularly an iPhone which I do not own. How could Wyze not work with a premier and current Android phone? I had my distant daughter visit to use her iPhone and before I could commandeer her equipment I tried my Android and it suddenly worked. Confused, but thankful. With that working fine for a week I attempted to install the 2nd thermostat and the same issue repeated. I swapped out the thermostats to confirm the wiring (confirmed) and then the first thermostat would no longer connect to the internet. It was only then that I accidently found the cure which was to turn on my Android GPS (location). Suddenly everything worked fine. I find that Android users are more likely to turn off or bypass GPS, so possibly that is why they have more problems…and frustrated that Wyze doesn’t mention that in their troubleshooting guide. Why GPS has to be turned on to install my thermostat using bluetooth is a significant question for Wyze to address, but at least I found out how to cure my problem.