Allocations of material to all work orders

All the materials have got allocated automatically to all existing work orders without user intervention.

For particular material x, I see that those work orders are in released status and, but their allocation had already fulfilled (X has been already issued)

some work orders are dated back to 2013

This has fully allocated some materials and user has to delete each allocations for each materials, in order to make them allocated for the correct material.

This occurred recently ,at the start of the current period. Allocation worked without any issue, and no setup change or patch applied recently.

I have also create a SR for this.