I can add a product with "title", "body_html", "vendor", and "product_type" and get an HTTP/1.1 201 Created response back and the product is created. However, when I try to add "images" or "variants", I get an HTTP/1.1 100 Continue response and the product is created. I would like to get the 201 response so I can tell the user it was successful.
Here is the request that is sent via POST to /admin/products.json, that in turn receives the 100 Continue response: https://gist.github.com/lukehatfield/8c719d7bcd4083861254d8b648880f38.
This app function is triggered via a button in the shop admin.