AMC no Dolby Digital

Trying to find out if I'm the only person that is not getting Dolby Digital on AMC. I've tried multiple channels, like 229 and 856 for example. I'm about 35 miles north of Atlanta. It's the same live, recorded, or on demand.

I only have one A/V receiver, so I can't compare multiple surround sound systems, but I tried an XG1v4 and XiD on it. I've tried Auto Detect and Expert audio settings. I get Dolby Digital on all other channels that support it.

I'm guessing it started a month or two ago. I first noticed while watching Walking Dead shows. I'm getting nowhere with Twitter customer care, though they're trying to help. I figure this has to be something in the feed from AMC to Comcast or Comcast to us. Would love confirmation from others and help from support here, if they see it. Thanks.