Silent/muted/no microphone input audio recording in WebView WebRTC after upgrade to AndroidTV 11 (NVIDIA SHIELD 9.0.0)

Hello, I have written an AndroidTV application that uses an Android WebView which uses WebRTC and HTML5 getUserMedia to record microphone audio input from a connected USB webcam on an NVIDIA Shield 2019 AndroidTV device. This used to work well on AndroidTV 9 (NVIDIA SHIELD v8.2.3), but after upgrading to AndroidTV 11 (NVIDIA SHIELD 9.0.0/9.0.1), the audio stream from the microphone is silent. The corresponding video stream from the webcam appears fine, though.

Is there a known problem with audio recording in Android WebView instances on the NVIDIA SHIELD 9.0.0 / 9.0.1 (AndroidTV 11) releases?

The same application appears to record audio just fine when run on various mobile phones with Android 11 and Android 12.