Material code quantity is not updating

Hello,

Only want to update the quantity of material code, but when i do it the system deletes the material, so I try to insert it again but I can't

I have checked the Material type in OMS2 and there quantity update/value update of perticular plant, i had seen here both value and quantity has flaged(ok tick is there), in OMS2 also it is ok

Plz do the needful answer

sapman