Fund management User exit - EXIT_SAPLFMFC_002 message problem

Hi Experts,

I implemented fund management and we are controlling budget by user exit (EXIT_SAPLFMFC_002) for monthly budget check.

When we create PO/PR, system logic passed warning message logic.

But, the warning message sometimes worked well, sometimes not worked. In case of 'Error message', there is no problem.

I don't know what is problem. Is there anyone know about this?

Thank you