Well, I never... (both my state secondaries where I am a governor had better 2022 results than the teacher assessed grades in 2021 or 2020 because they were scrupulous about accurate & fair assessment)

https://www.theguardian.com/education/2022/dec/24/north-london-collegiate-school-investigated-a-level-grades-2021-malpractice-allegations?CMP=share_btn_link