X1 DVR recordings pixelating...still

This issue has been going on for some time now - each time I am told the same thing, refresh the box, reset the box, the signal is good, blah,blah,blah.   I have rewired all the coax cable and only have 1 3 way splitter on the line coming into the house.  It gets to the point that I can't even watch the shows i record.  This happens with recordings on both the DVR X1 box and the extra box that I have in another room.   However when I test using the xfinity stream app everything is fine,  no pixelation -    What else can be done to troubleshoot this - can I get a tech to check the line outside because I know the lines inside are fine.  Can I get a new box to see if its this DVR that is bad.   I am about to cancel this service if Xfinity can't fix this issue.   I pay too much to constantly have this issue