SUMMARY
On Brave v1.83.109 with AgentDVR (https://www.ispyconnect.com/docs/agent/about).

On page load/refresh, the Live video page shows UI elements, but video frames are blank. Switching to another page such as Time Machine or Recordings and back to live video resolves the issue.

Brave console log shows :
/?viewIndex=0#Live:1 Uncaught (in promise) AbortError: The play() request was interrupted because the media was removed from the document. https://goo.gl/LdLk22
monitor.min.js:168 Uncaught (in promise) AbortError: The play() request was interrupted by a new load request. https://goo.gl/LdLk22

STEPS TO REPRODUCE
1. Enable Plasma Integration extension
2. Browse to AgentDVR live view page

OBSERVED RESULT
No playback, errors in console.

EXPECTED RESULT
Automatic playback, no errors.

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 42
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.18.0
Qt Version: 6.9.2
Kernel Version: 6.16.10-200.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-7700K CPU @ 4.20GHz
Memory: 32 GiB of RAM (31.3 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 3070 Ti

ADDITIONAL INFORMATION
Disabling the extension resolves the issue.
https://www.reddit.com/r/ispyconnect/comments/1nyrei4/video_playback_fails_to_initialize/