REST API: Batch updating products creates a new product instead

When I try to batch update products using the REST API, the products don’t get updated, and instead a single new product with the name “Product” gets created.

This is what I’m sending: https://pastebin.com/14upemus

And this is the response: https://pastebin.com/3UBphGez

Could it be possible that the products don’t get updated because in the data that I’m sending, there are some properties that don’t match the schema?