simple fact: bronze+silver+gold means broken
riot.. there seems to be complaints about matching.. and some efforts on your part to fix it.. but the obvious, and NECCESSARY, is not happening.
There should NEVER be a ranked game with a mix of bronze, silver, and gold. Never. It always come down to where the golds are, and everything else is irrelevant.
The whole 'separate mmr for duo and flex' is a farce, leading to this kind of junk. also, occasionally, duo-ing in duoqueue can lead to this sort of thing as well.
Please put some kind of hard limit in place, so that this cannot happen any more. Take rankings from one queue into account, for the other one, please.