ReverseFulfillmentOrderLineItem.fulfillmentLineItem field is nullable as of 2024-10
API
Effective August 30, 2024
Action required
As of 2024-10, ReverseFulfillmentOrderLineItem.fulfillmentLineItem field is nullable. A ReverseFulfillmentOrderLineItem will not always be associated with a FulfillmentLineItem anymore. The non-null fulfillmentLineItem field on the older API versions will return a graphql error when the fulfillment line item does not exisit.
Learn more about ReverseFulfillmentOrderLineItem on Shopify.dev.