Defenders not marking single striker

I've just had a game where the opposing striker got two long balls over the top and ran through the middle of my defenders. Neither was anywhere near him despite having man marking and tight marking enable, I don't usually watch replays so I was unaware of this but it looks ridiculous. Is there anything I can do to stop the striker having a huge hole to run into? Playing deep? A third defender? Sweeper?

Just for reference that striker had four clear cut chances and I had zero despite also playing one striker and getting more shots on target, possession and better passing.

Defending is a known problem.

Defenders seem to get confused with the lone striker so I set one of them to be man specific when this happens.

Defenders seem to get confused with the lone striker so I set one of them to be man specific when this happens.

I think this is the case as the other striker (they started with two) got sent off and they played much better with just the one up front. I'll try man specific marking in the future and see if it makes a difference. A lot of teams in Spain play with one striker.

Defence is very problematic, but I have countered this problem somewhat by playing a very narrow game. With no width to my team, my players all work together far better in closing down opponents + the opposing team can hardly ever find anywhere to pass the ball through. Also, the narrowness of my play doesn't hinder my attacking as I have no wingers and play with a DM, CM, two ATT.Ms and two FWDs - all playing in a straight line through the pitch; I call this strategy 'The Tornado'!