First clean the screen properly. Use vinegar and newspaper.
Second ensure your blades are less than 12 months old.
Third Make sure the arms are square to the screen. You may need to give a slight twist to the end with some grips. If it does not improve, twist in the opposite direction.
I speak from years of experience with this.
Last success was with my wife's Matiz. We bought those new all rubber blades but still had squeek, judder and missed bits. A quick arm twist sorted it completely!