I currently have a case open with Microsoft around call quality issues when utilizing Vista and MOC. These issues can occur with a Catalina or any other device that is connected to your PC. We have found some interesting information in the process of troubleshooting and hopefully soon there will be a fix.
In the mean time I’d like to request that anyone who is having similar issues (lost syllables, clicking or popping sound, etc..) when using MOC email me with details of what they are seeing including build info on MOC and the machine. My email address is Kevin (AT) this domain. I look forward to hearing from you!