2 Iron

RE: Trouble with XPS 15 9550, USB-C/Thunderbolt 3, and external monitors

I'm running Windows 10 pro. As I said, normally I run with the laptop lid closed and my external monitor connected using the laptop HDMI port and everything works perfectly. It's only when I try to use the TB15 Thunderbolt 3 dock and connect my monitor to the HDMI port on the dock that I experience the problems. My monitor also has a VGA port so I did try the VGA port on the dock rather than the HDMI port and experienced the same problems. Based on what I am seeing, and others, like you, reporting similar problems, it seems pretty clear it's a driver issue. Hopefully Dell will get it fixed sooner rather than later.