I can't say when the issue started. At first I thought it was me, but no. Here's what happens:
The TV is in Live mode and I want to restart the program. I use the down arrow to get to the "Restart Program/Pause/Live" choice. I arrow left to restart and at best it goes to about a minute into the program. Well, that's not really the beginning beginning, but close enough. Watch the program, commercial comes on, hit FF and the time bar jumps back to the point where it started from, not from where I want to FF. So that means I'm FF-ing through what I've already watched plus the commercials. Hit Play (let's pretend it's 12 minutes into pgm) and watch some more, then next comm break, hit FF. Yep, jumps back to where the 12 minute mark in the example where I again get to watch what I've watched. I finally get frustrated enough to just go into Live mode and swear.
I hope that makes sense. What's really irritating is that sometimes it works, most of the time it doesn't yet it used to always work perfectly.
I'm going to take my life in my hands and attempt a phone call to Comcast and to save you from wasting your time with the usual suggestions, yes, I've rebooted, yes, I've checked all connections, yes, the remote has fresh batteries although you'd have a hard time convincing me weak remote batteries could tell the system to go back to the exact point in time where I've already been but I'm willing to listen if you have something else that's logical to try.