Joseph correctly observed, It is possible that some parents enrolled their under-performing child in a charter school to escape a traditional school, and it takes a while to decontaminate the student.
We see the same thing in the homeschooling community when a struggling child is “brought home”. It’s sometimes called “de-schooling”; if a kid has had a bad time in the schools, it takes a while to convince them that (a)”learning” is not the same as “classroom”, and (b)things are going to be different now. Our advice to families is usually to make a commitment to themselves to homeschool for a full year simply to get themselves over that transition. The first two months seldom look like the eight and ninth.