Commercials cutting in on tv shows and sporting events when it is not a commercial break. This is causing viewers to miss minutes of shows and games.
Any show being watched after the original showing on a channel may have had some commercials changed to be current. The person handling the duty may be new or filling in for the normal person.
Mistakes can happen if a commercial is not inserted at the proper time. Sometimes this type of error may be corrected on some later time or day.
@Marleecakes wrote: Commercials cutting in on tv shows and sporting events when it is not a commercial break. ...
Especially if the ads are for local or regional advertisers, Comcast's Spotlight service may be responsible. See http://www.comcastspotlight.com/.
This is almost certainly the problem. Sometimes it's Comcast (especially if it's a business in your immediate area - for example, someone in Napa watching a San Francisco station getting an ad for a Napa business); sometimes it's the local station inserting its own ads (this is how the station makes money). The networks are supposed to make it clear to the stations when the ads are scheduled to air, but occasionally there will be a change - for example, an episode had to be replaced because it included a shooting scene and there was a school shooting a few days earlier, or a scheduled new episode had to be replaced with a repeat in the west because a long-running football game caused it to be pre-empted in the east - that catches everybody off-guard. This is also why, during, say, the Super Bowl, the announcers will use the phrase, "a word from your local stations"; that is a cue to the stations to run one of their own commercials.
You think that's bad? One of the reasons I switched from Comcast to U-Verse about eight years ago was, a lot of smaller stations would air infomercials overnight, and Comcast would replace them with their own infomercials, but when daylight saving time ended, Comcast didn't realize it, and ended up airing an hour of infomercials over entire programs.