Garmin tech support was my first option on the first problem and they were of no help. Since I got my entire G3x setup from SteinAir I called them next and their customer service is nothing short of amazing. I had a few questions and they walked me thru all of them.
I do recommend you pin out every plug. I found one plug that 2 wires were reversed. It wasn't a big deal but none the less people are human and stuff occasionally happens.
As for the software update, that is where I would start too.