Unit of Measure field Disappear in Basic data 1

Hi folks!!

I am facing a starnge problem.

In Material Master Basic Data1 tab, Unit of Measure filed is not appearing, I have checked Field selection config, there in field selection group , MARA-MEINS for material type and T.Code MM01 this field is set to optional. This shows that this field should appear in MM01 Basic data1 Tab.

Please advice, how can I make this field available in Basic Data1 Tab for input.

Best regards.