It's called dynamic ad insertion and it is done by every major distributor in the US.
I am familiar what dynamic ad insertion. This is different. It happened last night on playback of The Expanse while it was still recording. I am thinking Dish has started doing something new with U511, and I am not a fan of how it works. It is like they are assuming we aren't going to FF/Skip commercials, or perhaps the code they use to detect the point at which the inserted ad should play has a bug which causes it to play over content instead of other ads.