It is not currently possible to change the reporter of Jira issues from the Vanta UI. The reporter will always be set to the person who initially connected the Jira integration. If you wish to change the reporter, you will need to reconnect (not delete) the integration. Please ensure that you have admin permissions in Jira before reconnecting.
Prerequisites
Administrator access to Vanta
Admin permissions in Jira
Resolution
Sign in to Vanta and head to the Integrations page
Scroll down to Jira and click Manage, followed by Edit
Click the purple Connect Jira button
After following through with the connection, the integration should be reconnected, and the user who reconnected the integration will be the reporter for all tickets moving forward.