New UP locomotives and those retrofitted with PTC equipment have 2.4 GHz WiFi antennas installed on the cab roofs. I believe the locomotives send diagnostic and event recorder data when in range of a railroad WiFi hotspot. What may be happening is the locomotives are trying to reconnect to the railroad hotspot causing your family to get hammered with too much RF as they pass by the house.

Have your family download and run a WiFi Analyzer app to determine which WiFi channel they (your family) use around the house, and also, what channels become active when UP trains pass by. Just keep refreshing the app as trains pass through. Take notes and observe multiple trains if necessary. Your family may be using the same WiFi channels as the railroad.

The good news is most routers allow you to pick a WiFi channel of your choice. If the railroad (or a neighbor) is the culprit, pick another channel far away. I recommend channels 1, 6, or 11 as they don't overlap like the ones in between.