Unable to Uncheck "Advanced Planning" checkbox

Hi Guru's,

We are facing an issue while unchecking the "Advanced Planning" checkbox in the material master . Even though the planning status is marked as "Marked for deletion". The system is not allowing me to uncheck as the checkbox is greyed out.

Is there anything that i have to perform first either at the Master data level or at the config in order to fix this. I am not able to run MRP live because to this. I am still capture.pngnew to PPDS so kindly help me on this.