Error while creating service entry sheet due to material group deletion

Good Afternoon SAP Gurus,

We have an issue where our finance team member had deleted a material group 01 and created an alternative material group Z01.

Now our user who was not aware of this had created a purchase requisition (PR) earlier with material group 01,Some days later when he was finding difficulty in making Purchase order (PO) with reference to that PR we had asked him to change the material group in PO.

Now again he is facing problem of material group while making service entry sheet.

Here I want to know one thing when we have changed the material group in PO to Z01 then how come system is picking material group 01 in service entry sheet.I have checked in EKPO table too where material group for that PO is Z01.

Then how is system picking material group 01 in service entry sheet.

Please help me gurus how to resolve this issue.

Regards,

Deepak