WD15 & Latitude 7x80 Needs to be reconnected after power loss

In my office I have a Dell WD15 USB-C "dock" that is almost permanently connected to a Latitude 7280. On an evening my laptop will shutdown, after which the plug socket is turned off.

When arriving to the office the next day, flicking the power on at the socket, results in power returning  to everything. However, the light on the USB-C cable from the dock, is not on and I have to disconnect the USB-C cable from the laptop and reconnect it before the dock wakes up.

From there, I am able to use the power button on the dock to power up the laptop.

USB Powershare IS enabled in the BIOS.

Am I missing something? It's a bit annoying.