Dear Jorge,
Check your configuration settings for Framework order.
SPRO >> MM >> Purchasing >> Purchase Order >> Define Document types >> see which 'Filed selection key' assigned to your FO document type (standard is FOF).
Then see the setting of field selection key.
SPRO >> MM >> Purchasing >> Purchase Order >> Define screen layout at document level >> go to details of field selection key >> goto 'Reference data, item' details.
Check which option is selected for outline agreement.