Unable to Update Contract Lines via REST API

We are currently trying to perform a data fix on our Contract Lines via REST API. The REST API we are using is REST API for Sales and Fusion Service in Oracle Fusion Cloud Customer Experience - Update a contract line.

When executing the REST API to update the Contract Line Number, we do not encounter any error. However, when checking on the UI, the Contract Line Number is still the same.

Please note that we have executed the REST API to Amend the Contracts as well and have also updated the Amendment Effective Date. Hoping to see a solution from anyone here. Thanks!