We've just implemented a process where the reporter needs to be modified on creating an issue.
As a service desk agent, you can edit the reporter and the reporter is visible on the create form.
As half of the business do not use JSD, they are just Jira users, the reporter is not visible.
In the service desk permission scheme, I've set the permission for "Modify Reporter" on the service desk project to be "Anyone on the Web" and also for argument's sake, added the Jira users, to no avail.
Do you need a service desk license when creating a call, to be able to modify the reporter?