In 2018, UK cannabis law was updated through changes to the Misuse of Drugs...
https://www.tntmagazine.com/leisure-entertainment/leisure/why-is-cannabis-still-illegal-in-the-uk-the-history-behind-medical-cannabis-law/
In 2018, UK cannabis law was updated through changes to the Misuse of Drugs Regulations 2001, not the Misuse of Drugs Act 1971