I don't know what you are complaining about here, but I remember Brazil lost to Germany 7-1 two years ago. This stuff happens.

And yes, the game engine changed in the previous update, when they added the "Association" thing. It was an extremely obvious change. I did go on a rough patch in the first few days, winning only one league game, but I figured it out after five days and ended the season with four wins and one draw.

The problem here is that the OP somehow thinks he has the "perfect" formation and that such "perfection" should last forever. Indeed, there was one type of formation that was more advantageous over others before the engine change, and it was obvious that Nordeus fixed it. The OP refused to adapt, thinking that money could buy his way to victory, and subsequently got burned.

The OP calls himself a "Tactician", yet he refuses to adapt to changes... That's extremely ironic. A true tactician should know that no tactic would last forever, and any gamer would surely know that things change all the time.

There was nothing to complain here. Adapt, or lose.