Passthrough Intel NUC + Soundbar = Hell

I have problems with video stuttering or no sound. Happens with AAC, AC3, Dolby Digital, you name it…
Everything plays fine in Plex but in Kodi I’m going nuts.

Kodi Jarvis (Windows 7, Intel Graphics 6000) NUC5i5RY –> HDMI –> Samsung TV KS9005 (HDMI ARC) –> Samsung Soundbar HW-J7511R (Wireless)

So far, the best I’ve got in Kodi is the following but often the audio is not synced. 200 – 300 ms delayed:
Samsung TV: HDMI-sound = Bitstream
Samsung Soundbar input: Tried with “Multi Channel” and TV – no difference
Kodi Adjust display refresh rate = Off
Kodi Sync playback to display = On
Kodi audio output device = WASAPI default

Passthrough Enable on following:
Dolby Digital AC3 capable receiver and transcoding
Dolby Digital E-AC3 capable receiver
DTS capable receiver
TrueHD capable receiver
DTH-HD capable receiver

What am I doing wrong and why does everything work in Plex with great sound quality? Please help me.. I’m lost.

Thank you so much for your help!