Webhook event type "issuelink_created" is calling registered method multiple times occasionally

atlassian-connect.json (descriptor) which contains configuration of “issuelink_created” under webhook division to call server method which gets triggered when issue is cloned. But also observed server method is calling multiple times occasionally when issue is cloned even after returning 200 success response.
It’s happening only when multiple call to clone the issue is raised(min above 4) within a span of 5 seconds , not for one or two request to clone the issue.
Any input is much appreciated
Thanks in advance