yes the utility poles can cause interference, could be your issue, but I had this same issue, my packetloss at night would go from 9pm to the next day around 8am. I kept calling and calling, the maintenance crew kept coming to my house and calling me giving updates, they told me that they are just fixing everything they can, and it was the node giving issues, and house were backfeeding packetloss into the node, causing that loss. My loss isn't 100% gone as of now, it's low though, around 1-3%, and games are now playable during the night.