Sonos Plex Source Select

Getting “Error on select_source with Connection error” when trying to select a Plex source for Sonos media player. Can control already playing fone and can select those sources and plays fine from the sonos app. Any ideas?

I am getting the same error now. Just started after updating to the latest version of hassio. I saw from the release notes Plex was updated in the latest release which might have caused this.