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

https://josuesexpertblog.novacrestiq.com/posts/why-do-two-slots-with-the-same-rtp-feel-totally-different

RTP is a long-run average, not a session promise: 96% RTP means a 4% house edge over time. Volatility affects how uneven results can be. In a short session, swings can leave you well ahead of or behind that average.