Mulit-Room DVR

[KRSL]

For 2 -years I had multi-room DVR service - worked fine.   Suddenly, it has stopped working.  Note - no changes in confirguration.   I have gone through several long calls with VZ Tech Support - rebooted everything - put in a new cable between the DVR and STB, changed the splittter - still no multi-room DVR.   Tech says everything is fine in file - account shows I have MRDVR, and it's on my bill.  

Note, I can see and delete recordings form the STB, but not play them - box goes blank for a second then returns to the channel I was on.    DVR box works fine - records, plays, etc.    

Ideas welcome.