What is wrong with this lp gains? ( EUW Silver )

https://euw.op.gg/summoner/userName=Trauja

Press " solo & duo ranked only " I am silver 2 and my last game had an average mmr of Silver 4 and i got 16 lp by winning it.. what is the problem? It's that if u look back up to 4 days ago, my games had also avg mmr of silver 4..

In this 4 days i grinded 2/3 divisions with a record of 17 wins and 6 losses , now... why the heck I'm still gettin silver 4 mmr game after winning all games in this 4 days and why am I gettin 16 lp a win ? All of those wins mean nothing?

I'm legit curious , if there's some script i don't know, like something with my total win rate ( that is only 49.5% )