In 2018, UK cannabis law was updated through the Misuse of Drugs Regulations...

https://research-wiki.win/index.php/How_Can_Cannabis_Be_Class_B_but_Schedule_2_at_the_Same_Time%3F

In 2018, UK cannabis law was updated through the Misuse of Drugs Regulations 2001—not the older Misuse of Drugs Act 1971. This change allows specialist doctors to prescribe cannabis-based medicines like Sativex and Epidyolex under Schedule 2