DBUsers matching query does not exist. [5009]

Recently I changed my db name and user from phpmyadmin. When I tried to backup my site this error came. I think changing the db name and user occurred this. How will I fix it?

Prob solved! Contacted support. The fix is below,

Fix: “You need to revert you changes, and make sure your database name and database user was exactly like when you created it from CyberPanel. Because CyberPanel tracks it this way, there is no other solution for this.”