Screen capture init failing with MEDIA_DEVICE_FAILURE on widget overlay

Problem
The @genesys/web-messaging-sdk v2.8.4 blocks the screen recording pipeline on Genesys Cloud v11.23.0 when the overlay mounts. The MediaRecorder instance doesn’t start and it’s just hanging doing jack all. This broke the QA pipeline for 3 hours.
Code

const stream = await navigator.mediaDevices.getDisplayMedia({ video: true });
const recorder = new MediaRecorder(stream, { mimeType: 'video/webm' });
recorder.start(1000);

Error
DOMException: MEDIA_DEVICE_FAILURE - Could not start recording. Permission denied or capture target blocked.
Question
The allowDisplayCapture manifest flag is set but the widget still refuses the stream.