Problem 

There are no grid tables included in the Jira XML backup. Why?

Details out why grid tables are not included in the JIRA XML backup

Reason

As table grid user you should be aware that the data stored in the grid table is NOT included in the xml backup.
The reason is that the grid table can be stored in any database, and not necessary in the JIRA database. 

Secondly, even Atlassian is indicating that for production systems, you should rely on the native database backup tools instead of JIRA's
XML backup service. Check document here

 

Solution