Degradation of video quality for LIVE TV but not recordings

I am connecting to my stream from my chomebook running Version 76.0.3809.136 (Official Build) (64-bit) via my XFINITY online login , going to stream,  and connecting via an HDMI cable.  When I watch a recording it looks perfect.  Whn I go to live TV (any channel) the video quality degradates (doesn't look like HD) but plays fine.  

Thank you for your help.