There appears to be a minor bug in the latest beta 3.0.0.31 (I don't know if this was in earlier versions).

The volume seems to be off by 5% between Google speaker devices and what is shown in HomeSeer.

If, e.g., I tell my Google Home speaker - "Set Volume to 50%", HomeSeer will show it as 45%.
Similarly, if I set it to 50% in Homeseer and speak the request "Hey Google, what is the volume", the speaker will respond that it is 55%.

UPDATE: Further comments on this have been posted to the beta testing thread.