Orders are often forced to close out

Slippage is serious, and orders are often forced to close out without notice. Trading is suspended on weekend, and my order was forced to close out, causing me the largest losses of all. They said the losses were caused by the reason that the margin rate is less than 200%. But my margin rate at that time was not low, nearly 200%. When the trading has not been stopped. I planned to close the position myself, but the platform’s slippage forced the order to close out, leading to the biggest losses.