Has there been any proposed solution? I am having this  exact same issue trying to cast my Pandora music to Google Home devices. Unlinking/Re-linking does not work. Force closing the Google Home and Pandora apps and reopening them does not work. When I try to cast, I can hear my Google Home Device briefly ringing a tone to signify a connection was made but then the "Oops! We are unable to cast at this time" error appears and the connection is lost. ... View more