1 Nickel

XPS 9550 not working with TB15 Dock

Just received my 4th XPS 9550, previous onces had faulty motherboard, keys falling off, and faulty hard drive). I updated everything straight off of the dell website, including the bios. But I still can't get my thunderbolt dock to work. I plug it in and makes the noise indicating something is being plugged and unplugged. It looks like it can't decide between being on wifi or LAN and the Realtek USB GbE family controller keeps on disappearing in the device manager. I have updated that drivers as well.

XPS 15 9550 i7 500GB SSD 16GB RAM Windows 10 64 Pro

The dock will somewhat work if I don't have the LAN cable plugged in the back. I can't use any wireless devices (mouse) plugged into the dock because it stops working after a minute. I've also noticed the ASMedia USB controller has fault icon on it. Tried updating those drivers. Every once in a while, the second monitor will go in and out.

I have conducted all their diagnostic tests and all are good.

Anyone have any suggestions?

I'm a student and need my laptop everyday. If this is another hardware issue, I'm going to return it. I doubt the 5th unit in 1.5 months will be any different.