Apple TV not consistently listing “HD” by HD purchases—Why?

[Buck Rogers]

I bought two British TV shows in HD a day ago on iTunes—Sanditon and The Halcyon—but my Apple TV (Set-top box) doesn’t show the letters HD on the main/info screen of the television show. All it says is “cc.” Am I getting HD here? Other programs I’ve purchased say “HD.” Interestingly, on my iPhone, both shows are indicated as HD in the TV app. It’s only the Apple TV box where the HD marker is missing. As for the video quality, they seem HD and not SD (The Halcyon is particularly vivid), but I’d like confirmation that I’m really getting the HD I paid for. (sanditon seems a bit washed out, but I don’t think it’s SD.) Any thoughts?