There are very few cases in which the fund deduction is unsuccessful in the month of fixed investment, and it will only happen when the money in your bank card is insufficient in the month. It will be deducted for two months when it is replenished next month. Generally, it doesn't matter if it doesn't exceed 3 months. If the net value of the fund is high on the deduction day next month, you will suffer, and the share you buy will be less, and vice versa, depending on the luck of that day.