Cannot enter Default Stage Locator in Release Sales Order form getting error "enter value in segment

We are on 12.1.3.

When we go to the Release Sales Order Form to pick a sales order  and select a  pick release rule ,the default staging subinv defaults from the  rule but not the locator defined there and if we try to enter one we get an error "enter value in segment MFG_ORGANIZATION_ID before entering value in locator segment"

We have to close the form and do a Change Organization >select the appropriate Org >Enter the release sales order form>then we are able to enter a value in the default staging locator field.

1.Why do we need to a chnage organization to be able to enter the staging locator when there is no error in the default staging subinv field?