loss of direct tv signal

What streaming devices? What error code do you get? Does this affect mobile devices as well? Have you tried restarting the device?

What service are you referring to? You mentioned DirecTV. Do you mean the satellite service or the internet streaming service, DirecTV Stream?

Direct TV stream

Have you rebooted your modem and router?

As i understand it ATT has wired my apartment with a modem and router

So all renters access the same router and modem? Have you checked with any others to see if they are having internet issues? It may be an issue with their gateways.

Assuming you are using the DTV Stream streaming device - the one I have occasionally loses WiFi connectivity, and no longer sees the network (even though other devices do).  In those cases, I have to reset the device, by pressing the red button on the side (just momentarily - a long press does more serious things).  It normally then will come back and connect, though it usually takes a couple of minutes.