What should I do if the main line is always broken above the fishing eight-character ring?

You said that this problem may be caused by many reasons, and we must find the problem before we can solve it. 1, the minor line is greater than the main line. 2. There is burr at the main line end of the figure-eight ring, and the main line is cut off. 3. The main line and the auxiliary line are not the same brand, and the tension of the main line is less than that of the auxiliary line. 4. There is something wrong with the quality of the main line, and the line diameter is uneven.