My s21 ultra phone app is very slow and laggy, it was already laggy before I updated to one ui 4.0, but now it's just way worse, sometime if I search for a contact it takes 10-15 seconds to show up. Also, sometimes when i call someone the app calls the last person that i called intead of the person im trying to call. This is very bad. I don't know what's the solution. I already did the soft reset and force stopped the app, but nothing improved. so I'm not sure what I should do to fix this. Someone please help!