Many people using Google Nest speakers set up as a stereo pair have been complaining that they are receiving the following error when trying to change the volume..
Sorry, I can’t change the volume on this device !!
Unfortunately, the problem stems from a legal ruling against Google from Sonos who say that Google infringed a patent relating to the volume control of multiple devices.
Google announced the situation on a community blog post shortly afterwards.
Since the update users must now adjust the volume of a speaker group or pair individually leading to many users being rightfully angry about the situation and saying that it renders the speakers “Not fit for purpose” or “useless”.
You can see for yourself the comments from disgruntled users here
https://www.googlenestcommunity.com/t5/Blog/Upcoming-Speaker-Group-changes/ba-p/77811