Apple USB-C Digital AV Multiport Adapter wont charge Ipad Pro 3rd generation

Hello, I have just received an Ipad Pro 3rd gen for my personal work which requires using a multiport adapter. I bought the official Apple one and while the HDMI and USB A ports work perfectly, the USB C port will not charge my device. I have tried multiple cords and power boxes, and I tried it on my iphone and the USB C port works perfectly. Any ideas why it wont work with the Ipad Pro?

Any help would be greatly appreciated.