HD channel available notification not working

Hi, 

We have had X1 for almost a week.   At first we were getting a notification with SD channels that HD channel was available.   A simple click would cause the TV to change to the HD feed.  Auto tune to HD also worked when activated.  

Although the TV was working well, our phones were very, very messed up. This resulted in a change in modems from a Cisco to an Arris.   Now we are unable to get the notification or to consistently apply auto tune to HD.    I have changed settings to no avail.

Is there a setting that may be helpful in getting the notifications?  Is there a system problem going on with auto tume or with notifications?

Thanks!