DVR recordings keep stopping

I got a new DVR cloud box because my old one was 5 years old. The new box was wifi , it didn't work because of where my wifi box was. The tech that came to replace gave me a new one that connected to the cable. Well that didn't work either,  when I try to watch a recorded show, it stops somewhere in the program and tv goes blank, the an error come on and tells me check cables and restart! That doesn't work! I get frustrated when this happens all the time! A tech came out to check and told me my cable was bad. Well they put in a new cable and it does the same thing! I checked with other cox users and they are having the same problem! Fix this this!