BEACN Mic's mute mode changes only respond to Windows-level mutes, not application-level mutes.
For example, currently BEACN Mic listens for the Windows device to be directly muted to change the LED ring (you can see this when muting the "Microphone (BEACN Mic)" recording device in Windows sound settings).
BEACN Mix Create, however, does not trigger a Windows mute. Instead, it triggers a virtual routing mute within the application which does not not affect Windows devices.
This is high on our priority list and will be in a future update.