Intel Motherboards : Z170 Gaming-ITX/ac HDMI 2 4K60 limited use issues

I updated my HTPC shortly with the Fatal1ty Z270 Gaming-ITX/ac and a Intel Kaby Lake CPU to get 4K ready.

Now I have exactly the same 3D output problem... I didn't get PowerDVD to accept the Display as HDMI 1.4 3D ready.

I tried the tip with "maintain display scaling" option and after I changed this, PowerDVD detected the Display as HDMI 1.4 3D ready.

But when I start a 3D Bluray, PowerDVD show that it can't start the movie on this display and failback to 2D.

I tried nearly any intel driver option but none is working, of course I changed the resolution to 1080p and 24hz for all tests.

Is there any fix for that issue? 

I had never problems with my two old setups and the nativ HDMI 1.4 ports, I guess the problem is the HDMI 2.0 port which is provided via a DP1.2 converter chip (same as from the z170 platform).

Sadly the z270 board has no addition old HDMI port, so I can't failback to any other option on that platform. :(

Buying the most expensive mini itx board to get nativ HDMI 2.0 without external GPU and now can't run 3D...