Frequent signal loss on 579 MHz only

The problem with that solution is that the signal loss is sporadic.  Here's the likely result:  Technician comes, the signal is fine during the appointment, technician leaves and closes ticket, then signal loss occurs after technician is gone.  So unless Cox is going to station a technician right outside my door until the signal loss occurs, your solution isn't exactly promising.

As I originally stated, I have eliminated my wiring as an issue.  I believe the problem is further up the network.  But again, if the loss doesn't happen when the technician is present, I could be going in circles.