Blusound products have a known issues with group sync and Roon. There is a thread about it. Take this one out and see if the rest kept in sync. You may need to adjust the sync delay to get them in sync but then should stick.
Blusound products have a known issues with group sync and Roon. There is a thread about it. Take this one out and see if the rest kept in sync. You may need to adjust the sync delay to get them in sync but then should stick.