I honestly understand your point of view here, because I used to think about slot numbers in a very similar way. 🙂
I also had a tendency to look at the data, total bets, return %, number of spins and compare what "should" happen with what actually happened. So I completely understand why 120,000 spins feels like a sample where things should already start getting closer to the expected RTP.
And to be fair, your question is not unreasonable.
The difficult part is that RTP is often misunderstood. It is not really a number that your personal play slowly moves toward in a predictable way, especially with high-volatility games.
And volatility is probably the most important thing here....
Many modern slots are very volatile, which means a big part of the RTP can sit in rarer, high-paying outcomes. Because of that, two players can play a very large number of spins and still have completely different results.
One thing that may also be important to consider: are you talking about one single game, or your overall casino history?
Because if this is across multiple games, the math becomes much harder to compare directly with a single advertised RTP number.
So even though 120,000 spins sounds huge (and honestly, it is a lot), for some very volatile games it still may not be enough for results to look anything close to the theoretical RTP.
That is why personal tracking can sometimes become frustrating for analytical players. You can collect a lot of data, do the math seriously, and still end up with numbers that feel impossible or unfair.
I also think your question about RTP versions is fair, because some games do exist in different RTP settings depending on the casino/operator.
The difficult thing is that from personal results alone, it is almost impossible to clearly prove whether what you are seeing is extreme variance or a different RTP setup.
So I really understand the frustration, because when you look at numbers seriously, a 64.8% return after that many spins naturally feels very far from what you expected.
I'm sorry for stepping in; I just saw a person with a similar approach and wanted to express support.