There are two likely possibilities: the app is not ‘provisioning’ the controller correctly, or it’s somehow incompatible with your network.
First, confirm that you can get the controller to have quadrant 2 blinking. Then, what happens when you try to set up Wi-Fi? Do the controller lights change? What error message do you get? Can your router see the controller?
Try a different mobile device if you have one. It need not have a working SIM, as long as it has Wi-Fi and can install the app. Or, try from your computer:
To rule out network incompatibility, temporarily set up a second phone as a mobile hotspot and try to get Rachio to connect to it.