Slots and RTP explained
Can a casino use an advertised studio RTP while running a lower RTP version?
Direct answer
This is a disclosure and regulatory issue: verify the exact version shown inside the game and compare with the local regulator's rules.
How to use this answer
A definitive win, loss, void or refund cannot be established from the question alone. Identify the operator, the exact market, the date and the relevant official result, then check the rules that applied to the bet.
Return-to-player and volatility are statistical properties, not promises for an individual session. A streak or a near miss does not establish that a particular spin is more likely to pay.
Reference: gamblingcommission.gov.uk · published rules or source ↗