What electrically affects connectivity of powerline adaptors

Tore deeper into this. I thought the PL1000 was working at other outlets on this circuit but I discovered it would work on initial plug in but lose connection about 20 minutes later. The unit does work flawlessly on other circuits in the shop. RIght now I have the PL1000 plugged into an outlet about as far from the office as can be but it works there. I plugged a D-Link wireless access point to the PL 1000 and use the wireless feature of my desktop to connect to the D-Link. Works quite well to get network access to the desktop but not the network printer or other devices.

I disconnected everything on the circuit leaving only the PL1000 plugged in but still no joy.

Fortunately the wiring in my pole barn shop is all exposed so I could trace back from the outlets to the breaker panel. I found some scary stuff along the way. I removed two piggy backed wire runs that should be on their own breaker, I found several places where the line was wire nutted together. Figured out why my exterior light wasn't working and fixed a few other things. Still couldn't get a good connection on that circuit. Better, but drops out after 20-30 minutes. Tried swapping breaker connections to another breaker on the same leg but that didn't help either.

Bought a roll of new wire, going to run a new line from the breaker panel to the office and eliminate all the splices. If that doesn't work then I have no idea what else to try.

There's a buried conduit that runs from the office to the house which I tried to pull Cat 5e though. Got a string though but can only get the cable about 75' then it stops. Think a tree root has collasped the conduit. :(

If the circuit re-wire doesn't work, my options are running Cat5e across the shop to the outlet where the PL1000 works or trace the conduit and dig out where it's collapsed and see if I can repair it.