Atlassian deprecated the actual Jira Get Create Meta endpoint in Jira Server from version 9.1.0 because they introduced a new Create Issue REST API in Jira Server version 7.0.0 which provided a more modern and efficient way of creating issues in Jira.
The Get Create Meta endpoint was used to retrieve the metadata for creating an issue in Jira. However, this endpoint was not as flexible as the new Create Issue REST API, and it required multiple calls to retrieve all the necessary metadata. In addition, the new Create Issue REST API provided better performance and scalability than the Get Create Meta endpoint.
Atlassian deprecated the Get Create Meta endpoint to encourage users to use the new Create Issue REST API, which is the recommended way of creating issues in Jira Server. Users who still rely on the Get Create Meta endpoint are encouraged to migrate to the new Create Issue REST API to take advantage of its improved performance and flexibility.
https://confluence.atlassian.com/jiracore/createmeta-rest-endpoint-to-be-removed-975040986.html
We refactored our implementation to use the new endpoint.
So if you face issues fetching the jira fields or seeing failure while creating a jira ticket in Harness workflow or pipeline executions ,
Validate if your jira version is v.9 and above, all you will need to do is ask Harness to enable the Feature Flags :
USE_NG_JIRA_CLIENT_ON_CG and ALLOW_USER_TYPE_FIELDS_JIRA for Harness First Gen and USE_NG_JIRA_CLIENT_ON_CG for Harness Next Gen Platforms.
Reference : Jira Integration | Harness Developer Hub