CLIENT PROBLEM IN CHAMP SELECT

I was plaing the new poro king and i was at champ select, swaping the new runes. I WAS IN THE RUNE PAGE. Suddenly the champ select stops and i thought someone dodged again, but in my surprise, I WAS THE ONE who left the match, also receiving a dodge 15 min timer ban. Did it crash? Did i do something wrong forcing the champ select to close?. CAUSE I WAS JUST SETTING THE RUNES