Change "fulfillment_service" "inventory_management" value to handle of fulfillment does not work

[nogamenofun]

I want to set the value "fulfillment_service" and "inventory_management" to handle of fulfillment ("ocms-xxxx-service")

However, the update product api return success, but the value does not get updated.

Below is the body I pass to "/admin/api/2022-07/products/<id>.json"

And below is the response: 

As shown above, the response data from shopify show that 2 fields does not get updated to the handle of my fulfillment service. Any idea what happen here?