KA and Grading Concern

  My Daughter has struggled all year with  khan 6th grade math When she completes a lesson it will not give her Mastery challenge at that time she is practicing something new each time and when she does get a mastery challenge they all show up at one time and that's about once a month. Then she will complete it at 100% then it bring her percent down 2%. It is very frustrating to see her go through this she has always been an A student in math. Now that we have gotten into 6th grade she has dropped to a B and its all based on the grade she gets from KHAN all of her school work home work class work are all good she gets 95 to 100% on all of that an KHAN is holding her back as her teacher counts this as part of her grade. She missed her quarterly percentage by 10% in the 2nd quarter. Now here we are in the 3rd Q and she still hasn't gotten to the 2nd Q level yet? I sit with her most nights and yes she is working very hard at this but as I said she can do it all right and she gets no points. So how is this helping it seems like it brings her down she knows this work. We have had multiple Parent teacher conferences with her teach but she has no clue either on what the problem is with this system. At this point she is only at 52% an was suppose to be at 60 by 2nd Q she had 54% last week her teacher was helping her with a problem they fixed it and it dropped her to 52%. I'm at  the end of my whit's to help. I know her teacher has to be as frustrated as we are since we email her a lot over the same subject. I would love for my daughter to be able to get the A she wants in this class but at this point all this program is doing is taking her self confidence an pushing it down. I'm not sure I'm in the right place to ask these questions but I'm tired of going to the teacher to here the same thing over and over I thought I would go to the source