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...
Source: https://www.gsmarena.com/google_pauses_roll_out_of_latest_duo_update_v30_due_to_call_volume_issue-news-30254.php