First Alert ZCombo will connect connect, help?

I have purchased 3 First Alert smoke and CO detectors to go in my home. I follow the exact instructions in the Ring app as well as the instructions that came with the detectors. I have followed the instructions to the "T" and all I see in the Ring app is "Adding device..." "Listening for Device". It goes no where and eventually times out. I have reset everything and repeated the process. I cannot find any troubleshooting anywhere? Thanks ahead for your help!