RTP is a long-run average, not a session promise: 96% RTP means a 4% house edge...

https://varimail.com/articles/does-session-timing-matter-in-online-casinos/

RTP is a long-run average, not a session promise: 96% RTP means a 4% house edge over time. Volatility shapes how uneven wins and losses feel. In a short session, results can swing sharply either way; a run tells you little about what comes next.