Get "unable to connect try again later.” Same error if share to or from the roam. This used to work before app update. The roam is now just a single wifi or Bluetooth speaker. It's not 8n the eco system. I used to like sharing the audio from my arc and placing the roam near my head to not distrub other sleepers. 

How are you trying to share the audio? Do you mean grouping the Roam with your Arc? In which case have you opened the grouping screen and ticked both speakers to group them, then press Apply?

Or am I misunderstanding?

I’m having the same issues and the same unable to connect message. 
I’ve got my turntable connected to the Sonos Five via Line in, playing fine. But when I try to group the speaker with a Move or Era 100 or Arc, the music cuts out, the error message comes up and nothing happens. Running all the latest firmware and software on the app.