When Carlos Sanchez plays for Colombia he plays in a way that's kind of different from most DM's in modern play. He's a anchor man. Back 8-10 years ago they had more DM's that played that way. Makelele for example. But they've been retraining and changing DM's positions a lot because the game has become much more offensive and less defensive.
https://www.youtube.com/watch?v=63WojjZy7QE See video on this position role.
He sits in the hole between the two central defenders. A couple yards up. His game is to mark the opposing teams #10 out of the match and break up play in the center part of last third of the pitch. He intercepts and opens up to the wingbacks who bomb down the side of the pitch to search for holes in the opposing defense. Often when Colombia's on offense he'll sit back as a second center back as a more attack minded CB rushes forward through the middle of the field in a Sergio Ramos type role.
Now it's changed. Most Modern DM's aren't even called DM's anymore. They're called holding midfielders. Their role is to hold up the ball and provide mobility. To assist the CM in controlling the tempo of the match. It's a completely different goal. A completely different role. They are a lot more offensive. A lot more mobile. They have to be much better passers and much better creative players. They almost function as a Regista.
This in general has to do with the evolution of football. It's no longer a game with defensive groups and offensive groups. It's total football, and not in the style that the dutch popularized it. In modernity it mean every player on the pitch is attacking when the team attacks, and every player on the pitch is defending when the team defends.
I'm thinking he wasn't given a clear role by the coach.
I do think he would do much better in a more tactical league like the Italian one that still values technical defenders.