DVR recordings starting late

For the past few years, every show on any channel that I recorded started about a minute before the actual start of the show, and was cut off about a minute before the show ended.  Now suddenly in the past week, every show on any channel that is recorded starts about a minute after the show began and ends about a minute after the show ends.  Is there anything that I can adjust on the DVR so that recorded shows begin on time and end on time?