Thanks for posting, and thank you for the great detail you provided, the troubleshooting that you performed and the quick follow-up letting us know that Airplane Mode helped.
For the benefit of anyone else following this thread, the article that speaks to using Airplane Mode or lowering the Wi-Fi transmit power as a solution for incorrect behavior that Joel mentioned is here -> http://plugable.com/2016/06/30/invest…
It is important to note that the Dell XPS 13 9360 has a ‘Killer’ brand internal Wi-Fi adapter that does not allow its transmit power to be lowered, so using Airplane mode is the only workaround for this system. Other systems that have a Dell-branded Broadcom Wi-Fi adapter or Intel Wi-FI adapter (many 9350 and 9550 models) allow for the transmit power to be turned down which can also help in many cases.
As mentioned in that post, it is also important to ensure all the latest relevant updates from Dell have been applied to ensure that USB-C and Thunderbolt 3 devices work as expected. As of today 1/24/2017, the latest updates for a Dell XPS 13 9360 running Windows 10 are here (apply them in the order presented):
Thanks for getting back with the update, appreciate you taking the time for the benefit of others following the thread.
You may wish to contact Dell regarding the issue, as in some cases customers have reported that after having Dell replace their system the issues with USB-C or Thunderbolt 3 devices requiring lowering the transmit power or the use of Airplane Mode were resolved.
I make mention to help ensure the behavior does not affect any other Thunderbolt 3 or USB-C devices you choose to use in the future.