5 Rhenium

RE: Dell XPS 15 9550 docking issues

The order doesn't matter.  The issue is that the latest BIOS updates released for a handful of systems, including your XPS 15 9550, have introduced intermittent device disconnects for USB devices connected via the WD15 and TB16 docks. There are several threads about this in this forum already.  So far, there isn't a fix.  The only driver updates you need are the ASMedia USB controller, Realtek USB Ethernet, and Realtek USB audio. Then you can optionally install the firmware updates for the WD15 and the Realtek Ethernet controller if desired.