Madness;
Get rid of look for overlap
Add hit early crosses
Make sure fullbacks and wingers are crossing more often
Cross to the near post
Keep the crosses whipped
Full backs should cross from deep (Defend duty might make this automatic)
Add Close down more
Mark their fullbacks or wingbacks with your wingers to try and stop overlapped crosses
Wingers should close down more
Fullbacks need to stay wider to limit space on the wings.
These may help you, if the things you are observing is why you are losing those last games
I have to say though while you can limit the crosses you concede they are very overpowered on this version of the match engine. Experimenting with the above options could help you though.
I have got this tactic working in the lower leagues. North/South and Conference. But I did need to tweak it.
I think Christian is testing with Ajax so you need to consider that.
P.S shocked you changed a tactic following 5-1, 3-1!