Ok fellow twinkle light aficionados, I gave up on UK sites for proper twinkling lights and headed to America. 🇺🇸
Amazon.com have a few brands that seem to fit the bill. Warm White, multi coloured and other options too such as bright white or red/red and green.
You can sign into Amazon.com with your usual Amazon account to buy. I'm afraid you will have to pay postage even if you have Prime but it's not terrible for the US.
They look good. I have bought one set of warm white enhon lights and they're exactly as they look on the review videos customers uploaded. Gentle twinkle not fast or flashing
You'll need a step down transformer but Amazon UK have loads of these.
I'll link the listings below but in the meantime I have compiled a video of a few review videos for you to see. There are loads more on the site.
canva.link/nurrsw0g49i8ig1