Yeah, that is exactly my feeling and the reason why I sold all the "big/expensive/high rated" players out (Eriksen, SIF Kimmich, Hummels, Kante, just to count a few).
Now I'm nearly back to my starting team with some good upgrades and all is fine. But I know the feeling you descripe... it looked like my players run slowly, made wrong passes or crosses... and I dunno why.
After I delete the team (ONLY the team, not my whole club) and create a new one, I switched back to the ones I loved (Toure, Smalling, Rose, Fernandinho, for example) and its all smooth again.
I decide to stuck with the team, cuz I don't want the same shit again. xD