Eter, GSM Watch, unresponsive buttons

I think this may be a bug - or I’m badly misunderstanding how things work.

I have Eter on my Watch Ultra, and it syncs stations nicely from iCloud.

However, when I choose a station to play on my watch, it seems to hurl at ignore taps. I can page through different screens of the UI, but just never reliably start streaming from my watch to my AirPods (I have my phone with me, but for weird reasons, would rather stream from my watch).

Is this a known issues, a magic feature of the new watch/iOS updates, or something I’m trying to do which isn’t supported?