The same happened to me. I have never failed an English Grammar Paper. However, I am unable to pass the Essay Paper. I scored 64 in PMS Grammar Paper. I passed English Composition in CSS Exams of 2017 and 2019. In CE- 2019, I scored 58 marks in English Grammar. However, I scored only 18 marks in Essay in both attempts despite the fact that I had passed the mock papers given by a very reputable teacher.
CSS 2022 will be my last attempt. Do you have any idea how to pass the Essay Paper.