SBC complection always failing from game menu

I can't complete any of sbc's from my game on PC.
I'm grind a lot sbc per day and prefer to do this from web application cause it faster. Often in web application i have some bug that doesn't allow me to complete SBC from it. Today i had that one again and i go to game and start grinding there as always. Cause Bundesliga end coming soon and i still want to pack some good players.
But after complection more that 20 80+ players picks i start recieving error about connection lost and kick to main menu when i try to confirm SBC. I'm in a frustration. Cause it's totally stopped any of pack/sbc manipulations in my game.
I tryed to reboot my pc, refresh my connection, and many of possible solitions, even reinstalling my game from steam. But it doesn't help 😞