My AVR's control app can't find the receiver, even though the receiver is on the network. How do I fix it?

This is a network problem wearing an AVR costume, and the fix is almost always on the router or the phone, not in the receiver.

Control apps find the AVR by discovery: the phone shouts on the local network, the receiver answers. Anything that stops the shout from reaching the receiver breaks the app, even while the AVR itself is streaming internet radio perfectly well. That combination (AVR online, app blind) tells you it is discovery specifically.

The usual causes, in the order I check them. Phone and AVR on different networks: phone on 5 GHz or on mobile data, AVR on the 2.4 GHz band or on the guest SSID. Put both on the same SSID and try again. Router "AP isolation" or "client isolation" switched on: this feature exists to stop devices seeing each other, which is exactly what you do not want in a living room; disable it for your main network. Mesh systems that have parked the AVR on a node the app cannot traverse, or that block multicast between nodes. And the AVR's network standby set to off, so the receiver is simply unreachable when it is "off" and the app has nothing to talk to.

Sequence that resolves most cases: open your router's client list and confirm both devices are on the same network; turn network standby on in the AVR menu; then restart the app, then the router, then the AVR. Restart order matters less than doing all three.

Still nothing? Run an ethernet cable to the AVR. Wired removes the band, the mesh node and the wireless roaming variables in one move, and in our installations it is the single change that makes control apps stop misbehaving permanently. A receiver that lives in a metal cabinet under a TV was never a great Wi-Fi client to begin with. Send us your router model and a screenshot of the AVR's network screen if you get stuck; it is usually a two-minute diagnosis.