Hello,
Is the issue resolved when you save or refresh the data in the planning board?
If not, you can analyze the steps of the decision table for graphical objects (/SAPAPO/CDPSC2 > Click on the Planning Board Profile > Charts > Resource Chart > Decision Table for Graphical Objects) and see if the object that is referenced is the expected object in the planning board.
Regards,
Yasmin Alayyan