1st game after winning a promos is always a loss

Is there something with the match making system that places you in a harder game immediately after winning promos? Ive been stuck in silver 1 for a little while, win streak, close to gold promos then losing streak back to s2. I always manage to get back to s1 but that first game is basically always a loss, basically 7/8 times. With teammates in the double digit death numbers. Now im not saying its their fault but is it a trend that you're placed in a game where you're expected to carry against a better team? Its almost always a gold 1-3 on the other team as well in those games. Seems way too common to just be a coincidence. Edit: Also, a losing streak usually happens as well, am i playing worst because i know i cant get demoted in those games? Im wondering if the matches are harder since Im usually on a win streak up to s1 no matter how far i fall in s2, but as soon as i win promos back to s1 its followed by a losing streak of 2-4 every time