Xi6-A Not Working

My Xi6-A wireless reciver is not working most of the time.  One issue it will go from excellent Wi-Fi signal to weak.  It is literally 20 feet away from my router/modem with no obstructions.  All other Wi-FI devices are getting a strong signal.

Other issue is 90% of the time I get a blank screen with no audio when I turn on the TV.  Reboot usually fixes the issue.  But what is strange is if I click the Xfinity button, go to Guide and select a channel I get a picture and audio with no issues.  

Is there some kind of setting which is putting the system to sleep and not activating the HDMI cable?  This is becoming very frustrating.  Any suggestions?