TV interrupted because of channel change?

Changing out the modem, DVR or STBs will have NO effect on the number of 'streams' your profile can handle.   You're at 1SD/3HD and changing equipment won't change that.

Could it be that a TV is off but the STB is left on?  The system will think that the stream is being used even when the TV is off. 

You need to be very aware of what is being watched and/or recorded (SD or HD) and on how many TVs are being used (no more than 4).

I wish it were as simple as a box left on. However, 3 people in the house watching tv all at once. 4th box has been off for a week and is set to SD only channels. 3 boxes on are all HD channels.
Tvs are working just fine then all of a sudden, the interrupt tv option pops up. Nothing has started recording, no other boxes are turned on. This message will pop up on either tv that is on at the time.
As I indicated, only thing that has changed was one person at that split second changed the channel. This past Sat, I was watching a show, the minute it happened, I ran to the bedroom and questioned the wife what had she done and all she said was change the channel. My daughter hadn't changed the channel.
On Sunday, my daughter came in and said the pop up happened. I hadn't changed the channel, and neither the wife that time.

So, there is no rhyme or reason to it.

Also the 4th box is in another room. It's only been in there for a few months. However, this issue was happening before the 4th box was installed, and same scenarios were in place. 3 tvs on watching HD channels. No recordings at all and all of a sudden the interrupt pop up.

As I mentioned in my OP, I have 1SD/3HD capabilities, so I shouldn't have issues running 3 tvs on HD channels.

Try a Whole House Reboot: 

Unplug everything....DVR, all STBs, RG (modem).  Wait 30 secs. 

Plug in RG (modem) first.  Allow all lights to come on. 

Next, plug in the DVR and allow it to become functional. 

Lastly, plug in each STB. 

Unfortunately, you will only know if this worked if you no longer have issues!

Just out of curiosity exactly what does your profile say?  Using the uverse remote press the following sequence:

menu->options->system->system information->system resources

Post all the steams, bandwidth cap, and egress info.

@skeeterintexas I'll have to do all that later when I get home. However, not sure what that will all do because we did that all in the that exact order when the tech changed out my RG, DVR and 2 of the set top boxes.

@_xyzzy_

Update...Wanted to wait a few days to see what happens.

After rebooting system as instructed and bringing everything online one item at a time, I still have the issues of TVs getting interrupted. No recordings are happening, only 3 HD streams running.
Latest episode. Wife was in the guide and exited out. I lost my feed on the DVR/TV.

As said no rhyme or reason which TV gets interrupted or when. I have also been noticing pixelation and slight freezing in the last few days.

I have no idea what is going on, but for almost $300/month for everything, this is not acceptable and something needs to be done.

Who do I contact now?

Hmm... I'm wondering if what you have is a race condition: while one channel is shutting down, and you're tuning to another, both channels appear to be "in use" and cause the "channels in use" prompt. 

Questions:

1) If only two TVs (and associated STB) are turned on and watching HD, and you change one of them, do you get the prompt?

2) if three TVs are watching HD, and one switches directly to an SD channel, do you get the prompt?

3) If two TVs are on HD, and the fhird one switches between two SD channels, do you get the prompt?

4) If two TVs are watching HD, a third watching a recording, and one of the HD users switch channels, do you get the prompt?

5) if two TVs are watching HD, a third watching SD and switches directly to an HD station, do you get the prompt?

6) When "Wife was in the guide and exited out. I lost my feed on the DVR/TV," did wife exit the guide by selecting an HD channel to watch, or did she select a recording or other screen?

7) How long before you can go back to watching the third channel after the prompt?  Seconds?  Minutes?

1) If only two TVs (and associated STB) are turned on and watching HD, and you change one of them, do you get the prompt?
     Yes

2) if three TVs are watching HD, and one switches directly to an SD channel, do you get the prompt?
     Never tried this

3) If two TVs are on HD, and the fhird one switches between two SD channels, do you get the prompt?
     Haven't tried that, But the 1 on HD changes, and the prompt comes up.

4) If two TVs are watching HD, a third watching a recording, and one of the HD users switch channels, do you get the prompt?
     The recording stays, but one of the others on HD will get prompted.

5) if two TVs are watching HD, a third watching SD and switches directly to an HD station, do you get the prompt?
     Never tried this directly.

6) When "Wife was in the guide and exited out. I lost my feed on the DVR/TV," did wife exit the guide by selecting an HD channel to watch, or did she select a recording or other screen?

     Exited out back to live tv once, and selected a channel on another instance.

7) How long before you can go back to watching the third channel after the prompt?  Seconds?  Minutes?
     Just press OK and the stream is right back on.


One other thing happened that was totally weird. Wife was home alone on Friday, with TV in bedroom on HD channel. She was on pc surfing net. TV got interrupted multiple times throughout the morning. Nothing was recording and that TV/settop box was the only one on at the time.

You mention racing. I have thought the same thing. These new settops/DVR and RG seem to be much faster than my last system. However, I had the same issue with the older DVR and RG.

I must say I've never experienced this sort of issue.  But I've got only 3 TVs and for various reasons, only one of them regularly watches HD at a time.  When I get that message, it is because of recordings.  Often it happens 1 minute to the hour when a new show starts to record and one that is already recording has not finished.  I have to wait 3 minutes for the before (new show) and after (old show) soft padding to elapse.  And sometimes there are three recordings going at once and only one TV can watch live.

I'm assuming that your U-verse equipment is connected directly to your U-verse Gateway via Ethernet or Coax (or in the case of the wireless, the WAP is connected directly to the Gateway)?

2 settops are connected via coax(DVR and daughter's room), 2 on WAP,(bedroom and spare room). Spare room usually off 90% of the time.

During football game Sunday night, I got interrupted 3-4 times. All those times was when wife changed channels on the WAP settop. The minute she changed channel by direct switching, I lost my stream. Didn't happen every time but that is what we have come to the conclusion that the issue is.

FYI, I have 2 wireless settops on 1 WAP receiver. Could that be an issue?

@cdasmiller

You've already invested so much time into this, I was merely suggesting changing the experiment conditions so it's easier to settle on an answer. Clearly AT&T believes your configuration is valid, but something is amiss and it's up to you to figure out the trigger. 

Perhaps your service just can't handle the config, or, there may a bug in their system for this use case. Because it is somewhat rare, I frankly would be very surprised if engineering support would pickup a ticket to work it for you.

I may be repeating something I said earlier, but if there are already 4 tasks in progress, and I believe pausing a live stream counts as one, a second set-top box will get interrupted. Happens here. The softpad before and after a recording does make this problem worse.

Well, I was wrong about the 2 settops on 1 WAP. I completely forgot I was having this issue even when 2 settops were connected via coax and 1 on wifi.
IDK what more to do. I've done the reboot and plugged in everything in sequence. I'm at wits end with this and I'm not a noob at this either. Been having Uverse service since Nov 09. Had this issue a while back and seem to have went away, but then comes back, worse than before.
Wonder if there is a tier 3 support that knows more? *sarc* Techs locally can't even figure it out.
Thanks for all the help. Even though it is mostly everything I have done in the past and now. 

Seems something is up, I've been noticing a lot more glitching since this has all started this time.

Can you post an equivalent screenshot to this?  Perhaps someone can spot a problem with service and make a suggestion.

Will do. I'll have to get that later this afternoon.