SEnt mismatch with GR

Dear experts,

I'm currently having problem with clearing old GRN using MR11. When I run MR11 againts the PO, it only display PO header but no items were display. Thus, posting is not posible.

I try look at the PO history and found out that SEnt value is different with GR value. One of the GR item does not have SEnt created. Is this possible?

I tried display the Material document and found out that Material field is blank.

So, how do i clear the balance on GRNI? Can I just reverse the GRN created?

Thanks for your time.