I found the problem and fixed it.
The 2 brown wires on the PS switch located on the driver's door were loose at the connector. I could actually duplicate the symptoms so I knew this was the cause.
I cut them, put on a new spade connector, shrinktubed them and it all works as intended. I think the issue was that the wires would get moved when I pushed the switch back into the door causing the sporadic working. It works every time now and my son even checked it out. I explained what I did (in 5 YO terms) and he was pretty happy. He suggested we "just take these windows out until I get older" but I told him that probably wasn't the best idea.
