Not sure what I'm doing wrong...

So right now I'm silver 4 and stuck in silver 4, every season before this I normally get stuck at silver 1.

I'm mostly a solo player and I thought maybe I just wasn't being good enough to carry but recently I started playing with a bunch of my friends. Most of these friends are gold or platinum players some are even diamond players. The diamond players will just get on their smurf accounts and play with me. I play shaco and early - mid game and even the early late game my game is very solid. I don't feed my CS is up my ganks are up my counter jungling and ganking is up. My gold by end of game is better than par. I focus on objectives not just kills and I know when to split push and when to team fight... Even my higher ranked friends all of them said I should be much higher ranked (not diamond but maybe high gold low platnum) like all of them say that...

My understanding of items and champions is way higher than anyone else i meet in my elo... my KDA is almost always better than anyone else on my team. (yes I do have the odd bad game not going to lie)

But everyone who is higher ranked and has played with me all say the same thing that I get really hard games... like I'm cursed... like my one platnum friend says they struggle harder in my games than they do in platnum games... and its not that I'm doing bad I'll usually have better KDA than they do 0.0 (not saying I'm better than them it just often works out that way)

So what am I doing wrong... I don't know what is it that is causing my games to be so hard... I'm a very good shaco like I've never played with or against a shaco who is better than me... (I'm fully aware there are shaco's better than me I've just never met them example shacolone or pinkward would defo be better than me...) but I'm still not ranking up... so what do I do... I know shaco can make it to challenger... other shaco's have gotten there... So I should be able to AT LEAST make it to gold... so I dunno I just don't get what is wrong...