Empty web hook body

In the company where I work we’re using GitLab Community Edition 12.9.4. Since some time when web hooks are triggered from GitLab to the Jenkins instance, we get response with status 500. After investigating log in Jenkins there is a strange thing because there is no web hook body (as if it has been send without body). History of send web hooks in GitLab shows correct web request with json body. Exception logged by Jenkins is “java.lang.Exception: Failed to read request body”. Everything works fine if we fire system hook or copy web hook json body and send it from Postman.
If anyone had similar problem I would be very thankful for any help.