[NUC] NUC Kits Can't be Powered via Thunderbolt™ from a Docking Station
Resolution
NUC Kits aren't designed to be powered via USB-C.
The Technical Product Specification specifies the Thunderbolt charging capabilities is only up to 5 volts, which isn't enough for the NUC Kit to function. By design, the board should be powered through the 12-19 V DC connector on the back panel.
