2420087 - ERROR: "Related Position is a required field/association in Object Matrix Position For Position" using onInit rules to create Matrix Position row

When trying to configure an onInit rule to create Matrix Position row, the rule is create and assigned as onInit to the Position object. The rule triggers fine when the Position is created but when you try to save the new Position you get an error messages:
"Related Position is a required field/association in Object Matrix Position For Position."
The error will repeat for every Matrix Relationship row you create using the onInit rule. For example, you use a rule to create 2 Matrix Relationship rows. You add the "Related Position" to both and try to save and you get the error.

"Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental." 

• SAP SuccessFactors Employee Central
• Position Management

Related Position is a required field/association in Object Matrix Position For Position, onInit, Employee Central, MDF-13952, MDF-13452, EC , KBA , LOD-SF-EC-POS , Position Management , Problem