Why you confused about the reference document number?
When you display the 103 movement's material document number, The reference document number will same Because it has no reference document number.
When you display the 105 movement's document number, then it should have the reference document of 103 movement's document.
Because you have done 105 movement type against the 103 movement types document number.
When you display the 122 movement's document number, then it will shows the 103 document's as reference number. Reason are same as above. Whatever its valuate or non valuate.. You are referring the 103 movement's document number. (you can't do 122 refer the PO number, you have to give the delivery note or material document number , which one is goods receipt)
When you have gone in MIRO, You are referring the PO number, and the reference document number is showing the goods receipt document number, as it is 103 movement's document number.
These all are standard behavior.
