@wklie, after updating the various firmwares on my N05xD (USB, NET module, I/F, etc), I cannot detect it with general UPnP-based apps (e.g., BubbleUPnP) from my iPad. Strangely, the official Esoteric Sound Stream app also does not detect it in my Android phone (but works fine on my iPad). I already tried the "usual" troubleshooting approaches (e.g., restart the entire newtwork from the router up to the Esoteric N05xd and android + iOs control devices; uninstall the apps and fresh reinstall; etc), with no success. Do you have any idea why this may be happening?
Make sure you're not getting a Network Error display on the N-05XD front panel when switched to its network input.
You did the right thing to power cycle the network starting from the router and include both Android and iOS devices.
This kind of symptoms usually indicates router operational instability from multicast. What router brand and model are you using? Did it update itself automatically (although non common this could occur)? Also describe your whole network, especially if you use mesh or any WiFi access points or powerline network.
In WiFi router set different SSID (name) for the 2.4GHz and 5GHz WiFi. Set the mobile devices to connect to each of them, see if it makes any difference to the detection.
Please try Lumin app, Tidal app (if you have a paid Tidal account), and Spotify app (both paid and free accounts should work).