Recently I came across an issue with some CMS WebRTC users where their microphones were not working when joining spaces. After some initial troubleshooting, we found that the Domain Group Policy was altering settings related to the Microphone preventing it from being used on the CMS WebRTC site. The setting in question is named Do not allows sites to access your microphone. Which can be found by navigating per the below points.

1. Navigate to Chrome Settings
2. Click Show Advanced Settings
3. Scroll down to the **Microphone **section
4. Observe that there are two options
   1. Ask when a site requires access to your microphone (recommended)
   2. Do not allow access to your microphone
5. If the later is enabled, certain sites can be allowed access by clicking Managed exceptions and adding in the URL of the desired site. Such as the CMS WebRTC (Web Bridge) URL

In the case of this scenario, the GPO’s were updated to include the WebRTC URL and the issue was resolved.

A simple problem with a straightforward fix. You may also notice the same settings exist for the Camera as well just below the Microphone section.