If it starts acting up again, you do not have to pull up the track. There are two ways you can improve connectivity on track that is already in place.
Solder a tiny bare wire jumper on the side if the rail, bridging the gap between two pieces of track just above the roadbed/ties. Be careful not to melt the roadbed/ties
Or drill a hole through the roadbed/ties and through the table top. Push the wire up from the bottom or down from the top, and solder a drop wire to the side of the rail.
