Well, tried it last night, no joy.
Switched the X Air to "static" and ensured it was 192.168.1.1. Made sure app clients had 192.168.1.1 configured. Neither one could find the mixer.
Behringer-supplied apps worked perfectly in this configuration.…
Got it. We're letting the router serve IP addresses, as that's how it's done 99% of the time. Except this time, I guess.
We'll nail down the mixer with a static IP address as you suggest, and supply it to the apps. I'll let you know if this does…