losing lp for 4th spot

As much as I understood I am not supposed to lose LP for being 4th and above? Why did this happen? Im not on loss streak either, quite opposite, I win more than just majority of my games. Also it should become possible to mute pings from people, since some people cant stop spamming. I disabled all sounds because of this, but I dont see this as the best possible solution. https://i.imgur.com/40IzBiF.jpg