So i saw a bunch of threads coming up complaining about placements, but it seems people don't know some things about it. Sure maybe some people werent placed where they supposed to be, but alot seem to not know how it works either.
FlexQ got soft reset, the highest someone could place was plat 1(this is where challenger players end up). Looking at some posts it looks like flex Q was bugged in a sence that not only some players were placed too low, but others were placed too high.
If after first placements you ended up close to your last season rank then you're one of those who got placed too high. General rule of thumb with these placement games is that you should lose 1 tier.
The fact that it's a soft reset it means that it's based on your previous season results, so you may go 10/0 in your placements and end up in bronze 5 because previous season you were bronze 5 too or you could go 0/10 and still end up in gold 5 because you were plat 1 previous season(just some extreme examples).
Hope this explain most of your questions.
Personally i ended season in plat 3 after first placements( i think it was 6/4 or something) i ended up in silver 4(way too low) and after the extra game im now in gold 5 which is pretty reasonable.