Reporter/Assignee field is not updated in Jira after being mapped
Problem
Reporter/Assignee field is not updated in Jira after being mapped due to an error in Salesforce:
Solution
Ensure that the IDs are correct both in Salesforce and Jira
Confirm that the Salesforce User ID is in an 18-character format.
In Salesforce Lightning Experience, use the Global Search to find the user under the People category. Select the display name to show the profile and find the ID from the URL.
In Salesforce Classic, navigate to Salesforce Setup > Manage Users > Users. Hover over the user to find the ID, and use this tool to convert the ID to an 18-character format.
In Jira Data Center, ensure that the Integration user has the Modify Reporter permission on the affected project.
Go to Project Settings > Permissions > Actions > Edit Permission > find Modify Reporter > add Integration user.
In Jira Cloud, the integration user is part of atlassian-addons-project-access project role, which by default has the Modify Reporter permission.