Have Direct TV, closed captions on all four TV's are out of synch with audio. Closed caption is 1 to 2 seconds behind audio

I have four televisions attached to my Direct TV service. All have their own box. Only one box has DVR. In the last 3 to 6 months, I have noticed that my closed caption is out of synch on all TV's. Audio is said and then matching closed captions appears a second or two later. They are not in synch as they used to be. Any ideas on how to fix, the cause, who to blame, etc.  Thanks for any feedback.