SXI_MONITOR - not displaying messages

Hi all,

     I'm using PI 7.3

     Since two days, I'm not able to check the processed messages in SXI_MONITOR. But the failed messages are being displayed. This is               happening only in my production system. Is there any settings to be configured or why this is happening?

If you see the below screenshot, there are total 268 messages found but only failed messages has been displayed.

Thanks in advance,

Jegatha