Same problem here: My speaker group has been working with Nest Hub in it
for many months. Al of a sudden the Nest Hub no longer wants to
participate in the group. All other speakers (Nest Audio, Max and Mini)
work fine. Casting directly to the Hub al...
Just to make sure: It is not just the Nest Mini, it is all Nest
speakers. I have 2 Google Home Max speakers on which I have not (yet)
noticed this problem. On my other Google Nest Audio speakers it is
definitely there and very annoying.