Firstly, you are up against more active managers (regardless of their team quality)

Secondly, in some matches in which you fail to win, it is considered a random upset result. Popularly known as troll results.

Thirdly, players have form and off-form cycle, so some mediocre players will have runs of 8-9 ratings and then runs of 5-6 ratings.

Fourthly, bad luck because a group of players are going through the same low performing cycle.

Just need to ride thru this and accept that you may not win the league, but a CL spot is a victory.

I've won the league last season with a fantastic group of players but this year they are very very mediocre in the league and my star AML is not providing assists/creating chances as frequent as he did last season. But I'm still in CL spot for next season, so it's not a big loss to me.

Quality of player has nothing to do with performance on the pitch btw.