I just watched the video, and the person mentions the anti-cheat mechanic, which reduces the shiny odds for players suspected to use a third-party software to automate their games. This was confirmed by Kyu and IT IS an actual thing. However, this administrator also mentioned that this doesn't affect the majority of players, just cheaters who hack the game, and it's not based on how many encounters you make. In your case it's just bad luck.