Bitstreaming of HD audio via Display Port?

I have a P2000 and problems with Bitstreaming audio via Display Port. When I use a passive DP -> HDMI adapter (and output only 4k24) I can bitstream all audio formats without problems. But when I use an active adapter and output 4k60 some audio formats (DTS-HD, TrueHD) don’t work. I tried two different active adapters, but the result is the same with both.

Any ideas? Do the newer Quadros behave differently?