The issue is now solved.
The latest stable branch (*4.2.2-48~g4fa99a6*) did it for me. I haven't mentioned before, but the first one I tried, even before the latest git pull (4.3) it was a docker container, but with a previous release version, that didn't work as well.
I am seeing a lot of improvement on video playback and none issue regarding sound. Which was the reason I set myself to look for a newer version from the start.
Thanks to Saen Acro, Robert Cameron for all the help.