I've set up HLS to use the Ext stream, changed it to H.264 and Baseline. The :8080/hls/show.m3u8 URL woks fine in VLC, however opening just port:8080 in Firefox browser or Chrome doesn't display the stream. It says unsupported.
Are you using the default video element to play it? You will need to use something like hls.js to upgrade the video element so it supports the m3u8
This is a firmware issue.
Do you had check Main Stream is ok?
Yes. The problem is likely caused by the embedded player in the firmware's web interface. Embeddig the HLS stream directly into other webpage on a server - that works fine.