Google has paused the roll out of Duo update (version 30) due to bugs. Justin Uberti, who is creator/lead engineer at Google Duo, revealed this in a tweet yesterday, blaming low call volume problem for the step they took.
Some Android users have reported low volume levels on calls with Google Duo v30. We've paused the rollout of v30 for now, and are in the process of rolling affected Android users back to v29.2. If you hit this issue, you can resolve by updating to the latest (v29.2) version.— Justin Uberti (@juberti) March 25, 2018
Google Duo v29.2, with a fix for the recently reported low audio volume issue, is now rolling out everywhere.— Justin Uberti (@juberti) March 25, 2018
So the update roll out has been paused, and the company is in the process of rolling affected users back to v29.2. In case you were troubled by low volume in Duo calls after the v30 update, you can quickly fix the problem by reverting back.
If it adds abilities to sell your person as a commodity they'll keep updating it, just like Facebook. #DeleteGoogle
You could also revert back to normal calling since google will kill this service eventually just like every other social app they have created.