Docker 8.x unable to select HDMI video output

[bakelitephone]

Software: FPP 8.x (all 8.x versions tried upto and including 8.4 but Screenshot for version 8.0)
Hardware: FPP running under a Docker container on Debian (Intel NUC)

Docker on Intel NUC

Same hardware docker & configs works fine with previous versions, specifically v7.5 (my current live version)

Symptoms: No option to select Default Video Output device as "HDMI" under FPP Settings > Audio/Video

(see screenshots)
It is not a massive issue for me at at the moment as v7.5 works really well on my Intel NUC (both video and is audio, better quality than a my PI) but it would be nice if this issue is fixed in future versions of 8.x (ready for next year).

For me over the last couple of years the Docker version has been a godsend as it is so easy to update versions while keeping my configurations/media/sequences intact. I also think the NUCs have better quality audio (no need for soudblasters) & video quality than my PI, plus docker/FPP on Intel NUCs has been totally bullet proof.

Regards & thanks

However worked fine under all previous (v6 & 7v) FPP releases

(See screenshot of v7.5)

Polar Express video (for projector) running on the same hardware but at v7.5 (also Ok of v6.x)

For completeness this is a screenshot of my Docker compose file as I run 4 FPP's (at different version on the same Intel NUC)