We have identified an issue that could cause audio issues when using Ecamm Live with a Blackmagic UltraStudio Mini Recorder and the latest Blackmagic Desktop Video software version 11.6. (Blackmagic released this version on July 17th.)
We will post a fix for this issue as soon as possible.
Meanwhile, if you have installed Desktop Video 11.6, you can work around this issue by installing the previous version, v11.5.1.