Missing the description causes the merge to be stuck state for half hour

Describe your question in as much detail as possible:
When the user clicks the merge button in gitlab, the user will be getting the message “The merge request is in the process of being merged” and it will be stuck for minutes.

What are you seeing, and how does it differ from what you expect to see?
Expected is to merge the commits


What version are you on (Hint: /help) ? and are you using self-managed or gitlab.com?
We are using 12.7.6 version and using self-managed

What troubleshooting steps have you already taken? Can you link to any docs or other resources so we know where you have been?
When we provide the JIRA Ticket and description while raising the Merge request , it is going fine.
But if any user forgot to mention description or JIRA Ticket then the issue is reproducible.