Volumio Premium question - 'Play here'

Hi guys,

Was wondering if someone could explain how this is meant to work? I’m sure it did in the past but now is rendered useless (i.e… nothing happens when I select Play here on my mobile phone remote, or on the desktop browser).

I’m using a Raspberry Pi 4 → Adi2 FS. Any way to create a device to mimic or create a new device, so I can play on the phone (including away from home) or on the PC. Admittedly there is no point on the PC if I have Tidal & FLAC collection with my other DAC & headphone amp).

Maybe I’m missing something, or there are some wrong settings, or something on the router is blocking this??