Gateway modem connection issues

We switched out our xfinity gateway for another because the modem was displaying a red light all the time. Everything was working great on it though. We were just concerned it was about to go out. We got home with our new one and hooked everything back up. There was a continuous blinking orange on the modem. We called xfinity tech support and they tried troubleshooting but no luck.  They told us to take the modem back and get another one just in case it was faulty. Brought home another new one and still same issue. Just blinking orange. We are currently waiting on a technician to come to our home. The thing is, everything was working fine until we swapped the modems.