Balancing teams on weekends vs weekdays

I would like to first bring up a phenomenon that reliably happens, and then ask for suggestions for how riot could fix it. THere will of course be idiots who claim "blah blah blah Statistics blah blah Math blah blah".

But here's the thing: statistics is only a MODEL. Real Life trumps models. If real life doesnt backup the model.. then the the model is WRONG.

So, here's the phenomenon. I'm a silver ranked player. That is approximately accurately my real skill level, so that gives you background on roughly what ELO I get matched with on norms.

During the week days, I usually fairly consistently win playing solo in norms. However, during WEEKENDS, I consistently LOSE when I solo in norms. Approximate numbers:

Weekdays: Solo win rate maybe 7/2 ? Weekend win rate maybe 1/7

I am playing the SAME CHAMPS week after week. and I have mastery 7 in them. So its not any kind of fluctuation of random "i dont know the champ this week" kinda thing. I'm guessing It is pretty much always a weekend thing of (I get matched with a premade of 3 or 4, and they FEED THEIR ASSES OFF) This has CONSiSTENTLY been happening. If riot wants to check my record on my solo-only games for the last few months.

There is something Fundamentally Wrong about matching on the weekends, for the general population ELO rating. It starts friday afternoon, and extends to late sunday.

i'm guessing it has something to do with riot's assumptions about "if someone is in a premade, they are good". but at the silver/bronze level, it is far more likely, "if someone is in a premade, it's just a bunch of casuals who dont know how to play, just screwing around for fun". So the pre-made adjustment factors are completely borked. Please, PLEASE fix this somehow.