In 2018, the UK updated the Misuse of Drugs Regulations 2001—not the 1971...

https://beauoynz053.lucialpiazzale.com/what-does-it-mean-that-cannabis-remains-controlled-in-the-uk

In 2018, the UK updated the Misuse of Drugs Regulations 2001—not the 1971 Act—to allow specialist doctors to prescribe cannabis-based medicines like Sativex and Epidyolex under Schedule 2. Recreational cannabis remains a Class B drug