Over in a similar thread about the Swift 3's usb-c charging issues i have discovered that (for the Swift 3) it requires a very specific 19.5V to start charging. However most USB-C Power Delivery capable chargers have fixed voltages (5,9,15,20v). it seems that usb-c power delivery is still in its infancy and imporperly marketed and integrated.
worth noting that other major manufacturers like Dell and HP have opted to use 20v which is pretty standard.
I'm sorry to hear you wasted your money on a dock already. That was my intention as well if the usb-c charger i had bought worked. fortunately i've managed to return the item to the store for a refund.