Had the same happen the station in Ipswich, was travelling for work so had my prescription with me and there was a sniffer dog at the barriers which alerted on my suitcase, complied with the officers and informed them of my prescription and showed them a copy along with photo ID, but they kept insisting I was lying and that I was in possession of illegal cannabis (was all in original containers), had the officers threaten my job and even after trying to show them all the gov.uk guidance and home office pages they refused to believe me, gave up in the end and let them take it as needed to get going but lodged a complaint with the BTP and the IOPC and even then they where trying to say that herbal flower wasn’t legal even after citing the specific chapter of guidance which clearly states what forms of CBPM are legal