placement series are bugged..

So..... Just finnished my placement games. won 8/10 games. I got "S rank" in all games but 4. i were gold 5, got demoted to bronze 1... How is that possible? I did my absolute best, and have been close to plat tiers. and i end up in Bronze? i carried 6 games pretty hard, was not toxic, or bad behaviour! Speechless... Link to my account:
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