First check in OMS2 against your Material Type if both Procurement type are allowed, if Internal is not allowed then you will have to change the indicator there. Only when both are the allowed the system automatically determines that value in here.
Then in OMS9 check if this field is mapped as hidden for the Industry Sector/Material Type/MM02 field selections. The order is taken in as Hidden/Display/Mandatory/Optionla, so if any of the selection has it as Hidden then it will make it as Hidden based on priority.
what is the materail type you are using normally raw materials have procurement type F as default
have a look at the link .hope it helps you
Kindly refer the below link. It may help you (But this is for hidden storage bin field in material master)
You can follow the steps provided by Biju -
1. get the field name as MARC-BESKZ
2.Use T Code: OMSR and enter that field name MARC-BESKZ and get Selection Group 55
3. Use T Code: OMS2 and click your material type ( with which the material is created) and in next screen check and find *Field reference
4. Use T Code:OMS9 and double Click *Field Reference (which assigned to materail type) and select field selection Group 55 & select round box of "Display" and save.
Also check your settings in tcode OMSA.