Repetitive process

Hi expert,

I am new to Repetitve Mfg process. My client is facing issue in running the process.

They have created planned order of 100 qty through MF50 tcode and then performed backflush of 50 qty. Stock increased by 50 qty and planned order reduced by 50. When they reverse it through MF41 stock get reduced but planned not increased by 50 i.e total 100 must be shown. Is it standard behaviour.