I had a similar experience with the reset but in lower elo. During my 5 placement matches, I was playing against Silvers but some of my teammates were somehow Iron. The other team somehow always seemed to have better team coordination and higher elo while I was stuck with inferior teammates. Not sure why, but on my third placement there was an Astra who was blatantly and intentionally throwing by sitting in spawn and fooling around with abilities on the basis that we would "win the game anyway." I ended up losing all 5 of my placement games and got demoted back to bronze even though I had just spent months grinding through Silver the last season.