When choosing a UK casino with a solid slot library and good RTP, remember that...

https://andysbestchat.lucialpiazzale.com/why-does-the-same-slot-have-different-rtp-on-different-casinos

When choosing a UK casino with a solid slot library and good RTP, remember that RTP is a long-term average payout, not a guarantee. Some slots offer different RTP versions depending on the operator