HELP: How to setup Samsung HW-K950 with Samsung UN50JU7100F TV, Cox contour box and Xbox One?

I am a complete newbie and trying to setup my home theater with HW-K950, Samsung UN50JU7100F TV, Cox contour cable box and Xbox One.

So far I have the HW-K950 connected to the TV on HDMI ARC which is HDMI port 4 on the Samsung One Connect box and my Cox contour cable box connected to HDMI 1 on the one connect box. I tried connecting the Xbox One to HDMI 1 on the soundbar but the atmos still doesnt work. Dolby access app on xbox detects the atmos supported soundbar but when I select Dolby Atmos as the sound ouput I dont get any output at all.

Can someone please either guide me to a post where it's been discussed before or help me understand what I'm doing wrong.

Thanks in advance.