MIGO - mat doc determined different GL accounts INV, VBR

Hi guys.

Normally, during month end, when users perform MIGO, the GL accounts in the material doc (for posting to Inventory Gain/Loss) are based on GBB INV in OBYC. This time around, the system assigned GL accounts in GBB VBR.

Anyone who knows what caused such behavior in the system and how to correct this? I compared the mat docs from last monthend with this month end and the docs are same in terms of company, mvt type, etc. Anywhere I can check why the system assigned a different GL account?

Thanks for your time.

Regards,

Rey