Fast forward and rewind dont work

Why the last 2 weeks cant I fast forward my recorded shows?????its really annoying this smart thing you put on it is terrible I used to have century link and a button press would skip all commercials your thing is garbage and stops too soon. But anyway today AGAIN every time I have a day off work I get to spend half of it with you! This is the 2nd weekend in a row I cant fast forward or rewind my shows!!! What's the problem??I only have One dvr box.