Duplicate handling Not Working

Hi PI EXperts,

I need your help here.

I am using the option of Duplicate handling in sender FTP channel as below:

Enabled Duplicate handling: Yes, Duplicate message alert threshold:0.

But I found few duplicate files are processed and archived twice?

These files have same name(with extension) , are of same size and last modified time stamp is also same.

Please let me know how I can resolve this issue so duplicate files are not processed more than once ?

Regards,

SV