In 2018, UK cannabis law changed through an update to the Misuse of Drugs...
https://wiki-dale.win/index.php/What_Are_the_Offences_for_Cannabis_Under_the_Misuse_of_Drugs_Act%3F
In 2018, UK cannabis law changed through an update to the Misuse of Drugs Regulations 2001, not the Misuse of Drugs Act 1971