previous channels button - Uverse

About 3 months ago, maybe more, I was no longer able to view the last 5 or so channels when I pressed the previous button on my remote. I LOVED that feature. Now it just goes to the one previous channel and I don't like it. We had the 5 previous channel feature for years! And, it still works on our other TV's, but not the one in my office. Just today we got a new cable box (U-verse) and it's still only the 1 previous channel. Anyone know how to fix it? Or if it's even fixable?