High elo matchmaking broken again?

Or is my MMR that good...? A Master and 3 D1s on the enemy team... We had a Master and a single Diamond 1 and then me at Diamond 4., not sure how this was fair matchmaking.

I mean we won and I did perfectly fine (only because I used to be Diamond 1 for a long time) but it was a very difficult game, obviously way harder than it should be for the LP I'm risking at this level. So is it just me (I've been on a pretty nice streak past few days) or is matchmaking broken again... cause this match is pretty suspect lol.