Chromium + its few derivatives are installed. Chromium, Brave, Opera as snap apps + Vivaldi from classic package manager.
For testing some Zoom meeting session is used.
PulseAudio audio settings tool indicates microphone activity on speaking to mic.
Zoom meeting session in Firefox - no problems with mic
Chromium and its installed derivatives all have problem to detect mic: message by Zoom + mic symbol meeting attendees panel is durable static (zero dynamics). Addressed browsers had to be connected manually to :audio-record slot. It however does not suffice.
While Zoom meeting session is established PulseAudio control app does not list failing browser in Recording session what seems to be suspect.
Admin disabled once chromium_ffmpeg snap app. Now it is back to enabled. However no snap app seems to connect to chromium_ffmpeg slot.
How to do further troubleshooting?
How to check if all used dependencies are installed?
Chromium derivative snap apps - NotReadableError: Could not start audio source
Vivaldi installed as classic package - same as above
Regarding Firefox please see thread opening message.
For all browsers Privacy Settings microphone is enabled, also snap run-time environment (in case of Chromium derivative snaps) connection to :audio-record slot is enabled, however manually,
Is ffmpeg snap app/package necessary for microphone to work in browser?
How to check stack of installed audio-related software for its completeness?
What got gum_test result indicate?
Right now mic works in no browser configuration, even Firefox fails, classic package and snap. Mic enablement was conducted at multiple levels. Firefox address bar presents red color mic symbol while Pulse audio GUI tool presents Firefox in recording tab yet its mic gauge presents voice coming to mic for open Firefox.
gum_test page show no interactivity, URL opens however tests virtual buttons doesn’t show any reaction.
Is ffmpeg possibly necessary for use of microphone in Zoom meeting?
In meantime a series of further comparison tests was conducted. In consequence of which myself comes to following conclusion: it is browser-based Zoom which is unable to connect to microphone.
Following observations lead to this conclusion
gum test PASS
Zoom meeting in Firefox, running on VB host operating system PASS
Zoom app running on Manjaro v.m. PASS
browser-based Zoom in any browser, microphone in meeting FAIL
For some unclear reason Firefox was working for some period of time. In course of troubleshooting it stopped to do so. In the end I am unable to recover that state / get back to it.
gum test works only if it connects browser connects to server with using secure connection.