Update: I found that if I say 'play on house' using the original home
mini both speakers will play. If I say 'play on house' using the newly
installed Google home device the 'something went wrong, please try
again' message results.
1 google mini + 1 google home device, each speaker is in a separate
'room', both on same - single network in google home app. When I ask to
'play on house' (default goggle home group) the speaker says "something
went wrong, please try again" and won'...