I use a XPS 9350 for about a year now. Its a certified refurbished with core i7, 16 GB and 512GB SSD.
I had an issue with usb C adapter tha has a lan port, HDMI port and usb 3 port. When I detach and reattach the adapter with laptop power on I almost always loose the external monitor (extended desktop mode) display. Display properties showed that cant detect the external display. the external monitor also goes to idle state. I need to turn off / restart laptop several times to get the external display on, sometimes for a whole day it did not come back at all.
I found a work around, when this happens go to display properties and change the "Extended desktop mode" to "Duplicate the display" mode and the apply, the other monitors get back to normal. you can reapply the Extended mode afterwards and it works fine.
I use kwmobile usb c hub.
I hope this post also help someone else. It s pity that a fine laptop has so much issues still to be addressed. (Auto wake up is killing me!!)