Jürgen Klopp has a worse points-per-game average vs. Man Utd than he has against any other English club.
Let's take a look at records:
9 games
5 draws
2 defeats
2 wins
1.22 points per game
And Klopp has never won a game at Old Trafford:
Man Utd 1-1 Liverpool
Man Utd 1-1 Liverpool
Man Utd 2-1 Liverpool
Man Utd 0-0 Liverpool