When on an active call in Virtual Office Desktop, other application will have lowered or no volume.
- Virtual Office Desktop
- Windows OS
This is normal behavior and is not caused by 8x8 app, but Windows OS instead.
As voice over IP (VoIP) services became more and more common here in the 21st century, Microsoft wanted to make the process of placing and receiving phone calls on the Windows desktop to be more seamless. To facilitate this, Microsoft added a feature starting in Windows 7 and present all the way through Windows 10 that attempts to detect when a user is making or receiving a VoIP call. When the operating system thinks a call is being made, it automatically lowers the volume of other apps (or even mutes them) while the call is in progress.
Reference Material on Tech Junkie.