If your GCast session is showing video but no game audio on Android, you may be hitting a recent Android regression.
Google is tracking it in Chromium issue 505414470, which describes a regression in Android System WebView 147.0.7727.55 where apps can receive silence instead of playback-capture audio until WebView updates are removed.
Why This Is Happening
From a technical point of view, this bug is interesting because it sits at the intersection of three Android subsystems:
- MediaProjection, which captures the app window or screen
- AudioPlaybackCapture, which grabs app audio for streaming or recording
- Android System WebView, the updatable mini-browser many apps use for embedded web content like ads, login flows, and in-app pages
The current signal from Google and other affected apps is that a recent WebView regression can break that audio capture path. So the video pipeline stays alive, but the audio track coming out of Android is just silence.
Because WebView is a shared system component updated through the Play Store, one bad update can hit multiple apps at once. That is why users are seeing the same symptom in GCast, Discord screensharing, and screen-recording apps.
Current Workaround
Before changing anything, make sure audio is not muted in the GCast website player.
If it is still silent, the known workaround is to roll back Android System WebView updates:
- Open Settings
- Go to Apps or Apps & notifications
- Tap See all apps
- Open Android System WebView
- Tap the top-right menu and choose Uninstall updates
- Reboot your phone
After Google ships a fix, you can update Android System WebView again from the Play Store.