RE: USB-C conmpatibility
I don't have a solution for you. But I had the same problem though Dell support initially told me that D200 is compatible.
However my Dell D3100 port replicator can be connected to USB-C slot in my Inspiron and works perfectly fine. I have also used a generic USB-C to Ethernet adaptor with my Inspiron and it worked fine.
It is a very poor engineering and support from Dell with their D200 and lack of knowledge about their product.