[safcsat]

So did some more testing, with following results:

1. HDMI directly from mainboard = Audio issues with all BD iso, AV-Receiver can't
recognize the audiostream. 3D starts and Projector switches to framepacked 3D
but video flickers and has KODI UI within the video picture....

2. DP to HDMI 2.0 adapter from Club 3D, no Audio issues. 3D never shows picture, projector
shows "no input"

3. Thunderbolt 3 to HDMI 2.0 adapter from Club 3D, same as DP adapter

4. DP 1.1 to HDMI (maybe) 1.4 adapter from Delock, just works for Audio and 3D

Edit:
So is there only one converter chip used in all adapters, or is there a chance there is an
adapter with another chip, which maybe works? ( maybe somebody knows : ) )

I tried with an old USB-C adaptor I have which happens to have HDMI 1.4 also (used it for my macbook.

It seems to work a lot better than HDMI direct. It opens the file straight into MVC (I think) as it doesn't quickly switch from SBS/TAB, just straight into a 3D mode. But it is not smooth at all. It is nowhere near as "choppy" as using HMDI direct, it doesn't flicker all over and have items from kodi menu in it...but it is not smooth. I checked the stats and CPU was only ever max of around 20% but it seemed to be struggling still to play the files smoothly.