QBI losses in one year carryover and are netted against QBI income (positive QBI) in following years. If the system will not let you enter negative QBI numbers, then, to be accurate, you will have to track these carryovers manually and enter the net of QBI income and carryover QBI losses in subsequent years. This is a hassle, but if you are working with large figures, this will save you from a bad outcome if you are audited.
