In 2018, UK cannabis law changed through an update to the Misuse of Drugs...
https://www.bookmarkidea.win/uk-cannabis-law-saw-a-key-update-in-2018-with-changes-to-the-misuse-of-drugs
In 2018, UK cannabis law changed through an update to the Misuse of Drugs Regulations 2001, not the Misuse of Drugs Act 1971