When renaming an issue type that is used in existing issues does not change in edit, create, and edit issue type from view issue.
- Create issue type.
- Create issue with new issue type.
- Rename new issue type.
- Check edit, create, and edit issue type from view issue screen,
The new name will be displayed.
The old issue type is still displayed.
Go to Jira settings > Issues > Issue Type schemes > Edit the desired scheme > drag and drop affected Issue type somewhere up or down on the list and then save the configuration. The Issue type can now be moved to the original position if required.
Restarting JIRA resolves this. Please see Start and Stop JIRA applications for reference.