Connect X1 to verizon stream soundbar

So I had Verizon FIOS and recently moved to Xfinity.  Verizon gave me a free soundbar which runs Google chromecast.  I'm trying to connect my X1 STB to the soundbar and then to my tv.  When I do this, all I get on the screen is "connecting to Xfinity X1."  Could there be some kind of setting I need to change?  I can connect it differently (X1 and soundbar to TV) but then I get big audio delays that I can't seem to fix.

I have TCL tv, Verizon Stream Soundbar (bang & olufssen), and the X1gv4 cable box.  I have read that the soundbar doesn't support 4k throughput via hdmi, but I've adjusted those settings on the X1 box and that didn't seem to help.