Mapping issue

Hi,

I am facing a funny mapping issue in which a message fails in sxmb_moni , so I take the payload from moni and run it in operation map or message map to see the error ,but it does not fail in test tab for operation or message map. Although it fails in moni.

Sometimes after restarting the message from moni ,it goes through successfully in moni also.

what might be the issue?

thanks