It's very easily explained by statistics and probability... there are big wins in most games, you just have to be lucky enough to hit them. If you play long enough, you will likely hit one - or hopefully, more than one!
Does it happen every time? If so, please put 200 euros in and video your session - so i can go to that casino and empty it of all it's money
Remember, you are much more likely to notice a big win when it gets you out of jail (i.e close to losing everything) than you are if you have only just started because of the sense of relief it gives you (as well as excitement)...
I wonder if you will answer this question that others refuse to answer:
Do you think that all the providers conspire, against the law and at risk of losing their entire business if caught, in order to compensate games when random games behave EXACTLY as you think compensated games do just through probability?
It would be easy to prove btw - record every single session you have and just note down all wins over, say, 20x. If you can prove that you get more of these when your balance is low vs when your balance is high, then boom - go to the Daily Mail
However, my guess (sorry, my knowledge) is that you will see no correlation between balance and profile.
If SG or IGT were caught doing anything like that, they would instantly lose their Nevada licence. Lose that, and all other regulators will follow suit. Bye bye multi-billion dollar businesses. And for what? It makes no sense whatsoever - i get the cynics in people thinking "of course they do it, money is involved" but if you gave some serious thought to what you're actually positing, it makes zero sense.