Yes that’s exactly the right takeaway. If they’re just using a normal cell number, there’s no routing layer to “catch” the fallback, so it will loop every time. In that setup, your only clean options are either a separate fallback number or upgrading to a VoIP/PBX system with proper call routing. Anything else is more of a workaround than a real solution. If you want, I can help you design a simple setup that still feels seamless even for small businesses