Why are none of my defense plays working anymore?

i’m a defense first player and I’ve been using the same defense for months with really good success and now i’m just getting shredded almost every game. None of my adjustments are working now, if I man someone up now they get wide open regardless if the receiver has abilities or not. I have a 96 overall defense with 98 Champ 98 Tradavious white and 96 deion. Literally everytime a reciever runs a route with a “cut” such as a slant or post they instantly lose coverage. What am I supposed to do? I’ve tried shading inside and underneath but they get open every single time. It’s to the point if I don’t guess exactly what play they’re running they will complete it every single time.