Related document shows many of the same document

I am using version 8 now. But even before v8, the later version of 7 had this issue also. I created a sales order, and use it to create material request. However, when I click the material request document link in the sales order, it will show multiple copy of the same material request in the document list. If I have 10 items in sales order, it will show 10 same material request in material request document list. This happens to other types of documents as well, like sales order → delivery note, etc.


I am unable to replicate the issue, refer the screenshot attached.

Is there any way that I can find out what’s the problem on my system?