Ranked Placements

Has anyone else had issues with ranked placements. I just finally placed in 6v6 for the first time ever after not really playing ranked since OW1. I played every game with a duo that use to grind ranked with since 2018. We both stopped playing ranked when it swapped to 5v5 and we both peaked low diamond. We placed and I got placed plat 2 and she got diamond 3 and every win since has been 30% up for me and over 100% for her, we've both been the two best players in the lobby consistently so why are we both so far away in ranked.