To clarify, there is no "solution" for this but there is a work around. You can plug a second device into the same side other USB C port, and this for some reason makes the laptop detect the SSD.As well as this I have had a bunch of other issues with the Xps 17 and I'm in discussion with Dell atm contemplating a replacement or a refund.... It is a shame because it is such a nice machine to work on.
Hey guys,   Just received my XPS 17. Mostly happy with the machine except that an issue has arisen in which my T5 Samsung SSD is not being detected by the USB C ports (or might be detected once in a blue moon). There is no issue with the device or cable as I tested them on various different laptops and it detected straight away. It also works if I plug it into the USB C to USB A connector. From what I can tell, power isn't reaching the SSD through the USB C to USB C cable. Any suggestions how to fix this? Awesome machine otherwise.
XPS 17 USB C Ports not working with Samsung SSD