MailChimp.Net/brandonseydel, adding a Cart Line duplicates the entire cart

Question

I'm using IECommerceStores and I tried to add a line to my cart like this: ECommerceStores.Carts(storeId).Lines(cartId).AddAsync(cartLine).ConfigureAwait(false);

The line is being added correctly to my cartId, but the entire cart was duplicated in my store carts collection.

Am I doing something wrong?

public async Task AddCartLine(string cartId, Line cartLine)
{
    IMailChimpManager mc = new MailChimpManager(_apiKey);
    string storeId = "Store-Test";
    await mc.ECommerceStores.Carts(storeId).Lines(cartId).AddAsync(cartLine).ConfigureAwait(false);
}

I've tried to update the cart with cart.Lines.Add(cartLine) and it gives the same problem.