Netflix, Youtube, Amazon Prime stop working partway into the shows

We can usually begin a movie but 20 minutes to an hour into the show we (usually) begin having problems.  Sometime the sound just goes out but the picture is fine.  Other times we get the spinning circle with some kind of a percentage listed and it just spins and spins and eventually blacks out with an error code.  The most recent was when watching Netflix and the code was NW-2-5.   I've called customer support several times but the best they've done was to tell us to reset the router.  Sometimes that appears to make a difference, sometimes not.