Rachio3 stuck on green and blinking Amber light

I installed the new Rachio 3 today and it worked fine for few minutes and then all of a sudden stopped working. Reading the description of green solid and blinking amber light, I figured it was having issues connecting to my wifi. Then reading other threads, I realized iOS 14.2 had known issue so I upgraded my iOS app to 14.3. Now I am unable to figure out how to reset the network setting of the controller. I also tried factory reset but that ain’t working either. Now my controller is removed from app and still stuck at green and blinking amber light. I can’t register it again to my app, making it totally unusable the day I installed it. Please help!

Serial Number: AC8414807
Model: 12ZULWC
RouteThis key: HMNJA22H