The issue originates when a user logs in to a VDA, and in the background automatically launching Skype for Business.  As soon as the application launches HDX Audio stops functioning. This only happens if the audio is set to "HIGH" on the VDA. When terminating Skype for Business and you reconnect to the session, the sounds comes back to normal. As soon as you start Skype for Business, the sound stops.

The issue occurs because the Citrix Workspasce App for Chrome/HTML5 does not support bi-directional audio apps (see the feature matrix here: https://www.citrix.com/content/dam/citrix/en_us/documents/data-sheet/citrix-workspace-app-feature-matrix.pdf)

Although it appears that Audio works normally in Medium or Low quality settings this may not work in a future version of Workspace App until bi-directional audio is fully supported.

Problem Cause

When Skype for Business loads, it breaks the HDX Audio, when Audio is set to "high" only. This only breaks on HTML5 receiver.