Unable to Cancel Material Document posted against Mvt 351

Hello Experts,
I created STO with Qty 100 PC, and Goods Issue w.r.t. Purchase Order Mvt. 351, 1 line item created properly and qty given 25, another line created manually 75 with another batch no., during posting system give error in line no. 2 as "Enter Purchase Order No." so i give it but the line item no. field disabled and system permitted to good issue.

when i see purchase order history it is showing only material document with qty issue 25 only

now i want to cancel my line 2 and system showing qty exceeded 50, IN MB51 report showing all material issued in mvt 351, in MB5t report showing only 25 pc in-transit.

Any idea what has happened?

Regards,

Mahboob