Bronze 4

since season 5 I was hoping I would get out of bronze. Last season I hardly played ranked and spent all season in bronze 3. I won 6 of my 10 placements and got placed in BRONZE IV. I really don't understand this. Could somebody please explain this to me. (I have over 500 wins in normal and I play normal often because of all my friends that play) (I concider myself a decent player probably around the silver 3 area) please help me out and comment below! I literally feel likme 'mmu right now :(