My take:
You also have a very patient build up play which means the opposition will more often than not be back in position and restricting the space by the time the ball is in the final third. I would of thought with your current tactic that an advanced playmaker may be a better choice to play balls into your forward, mezella and wingbacks. If you want to utilise the treq I'd consider removing play of defence TI to encourage the ball to go forward quicker, then there will be more chance for him to exploit the space, especially if he has good speed, dribbling and flair.
Your forward is on a support duty meaning he will drop deep - this is probably making it easier for the opposition defenders to mark your Treq as there's no one making runs beyond him and pushing the defenders back - which in turn would create more space for him to operate in.
It's also worth taking a look at his movement attributes (off the ball - anticipation - decisions) if these are poor then opposition defenders might find it easy to mark him out the game.