Did that and no change.

I connected the WiFi router the phone uses to the same unmanaged switch the 271 is connected to and it makes no difference.

Discovery is based on UDP or TCP multicast I think?

Anyway it doesn't work.

Main: Marantz Cinema 50, Meridian 271, DSP7200.2, DSP5200HC, DSP5000 rears, Meridian 210.
PC/Headphones: Mytek Liberty II, Sansui CA-F1, Sansui B-2301, Sennheiser HD800, Kef R3