Chromecast Audio renderer stops local video playback

[mr-b]

If I play a video and then select a Chromecast Audio CCA device as a Renderer then the audio is duly cast to the CCA but the local video playback stops.
How does one just cast the audio to a CCA device and preserve local video playback?

I see this on Windows and Android so presume it's a generic app issue.

[Kristop]

I have the same question, it would be great to just send the audio to a CCA and keep seeing the video on VLC. In fact it's the only way to watch a DVD, when using a CCA !