Facetime audio calls not working using iPhone

I have a Netgear Nighthawk MR60 mesh system with a WiFi router and one satellite. Since I installed it, I cannot make calls using my iPhone xs with either of my Mac computers. The window comes up telling me I’m using Facetime audio with my iPhone, but I immediately get a message in the window saying that the phone and the computer must be connected to the same WiFi network in order to complete the call.

On my Nighthawk app, all 3 devices show up on my 5 GHz network.

This worked with the former WiFi router I had and replaced. It was not a mesh system. That router had the ability to connect to either the 2.5 GHz or the 5 GHz network manually. Apparently, the Nighthawk does not have the manual connection option.

Has anyone else experienced this?