Port... am I missing something?

I have Port connected to a turntable & I am finding it the most confusing, clumsy & inconsistent device.
I don’t know if I have installed it the wrong way or if I am not understanding how to use it, especially to output to different rooms and speakers. It is driving me totally nuts.

‘Listen in every and any room’ they say. Not likely!

Example - I have a pair of Era 100s and a Sub Mini set-up as the turntable listening system. These are all wifi connected. I start the turntable running, select Port as the source and then press play and it works (although inexplicably it often cuts out play when you turn the record over, you have to press play again…)

In my main living area I have Arc, Sub and a pair of One SLs connected to the TV.

If I try to add that room as an output… nothing. The audio from the TV continues, it doesn’t switch to the different source, if I try with the TV switched off… nothing.

This doesn’t happen with other sources such as streaming from my iPhone or iMac or playing channels through the Sonos app. It’s just a problem with Port.
So… am I doing something wrong? Have I installed it incorrectly?

Any assistance appreciated.