I am having the same exact issue. Mine has also been several days. Says connection to opponent lost, or that opponent has left match. I am unable to play divisional rivals fut 19.
Division Rivals stuck at the loading screen after squad selection. Squad battles is working fine. Updated squads as well.
Stilll issue with this. And as ussual EA don't give damn, as long as money flows in. no solution, no support, nothing.