We have the same struggle with our 13 year old. Distance learning has only made it more challenging. During therapy it became obvious the need from external stimuli in the form of a more personal relationship with the teacher. When the personal relationship is there grades go up. When left to own devices it’s total failure and frustration in the household.
Because math is a repetitive task our child really struggled so for the last 2.5 years we enrolled in Mathnasium. That has helped a lot with math. Because our child is also gifted, if the subjects do not seem interesting then it’s complete shutdown. We do not believe in medication so we have been treating ADD and anxiety that accompanies it with now weekly neurotherapy/neurofeedback sessions along with regular therapy. Still getting F’s but as therapist said we can provide the tools but at the end is up to them to figure how to motivate and self-regulate themselves. What we have to do is just be supportive and assure them that there is nothing wrong with how they feel or who they are.
I suggest family therapy with an ADD specialist that will help to bring up all the emotions and feelings boiled up inside, especially when dealing with homework and grades. We have been learning a lot about our child since we have a hard time relating. Good luck.