my account traffic has stopped and no matter what amazon won't give me buybox

my account traffic has stopped and no matter what, amazon does not give me buyboxes. my account health is healthy and I have not received any negative feedback. after my store was approved, I sold for a week, then amazon took all the buyboxes from me without sending any notification, and even if I lower the price, I cannot get buyboxes from sellers whose delivery date is later than me. my account traffic has also decreased to 0. no one visits my store. i think this situation is caused by a haa in amazon, but I could not solve this problem with customer representatives, please help me.