I think SRH3's comment above regarding the error in TT is correct. I have a K-1 that had 2018 and 2019 QBI losses. TT 2020 comes up with an error saying it is missing the 2019 QBI loss carryover amount. But when I look at the form it looks like TT is adding the 2018 and 2019 numbers together and putting the total into 2018 and leaving 2019 blank rather than putting 2018 in 2018 and 2019 in 2019. This is still the case as of 26-Mar-2021, after updating TT Home & Business. When I manually change the 2019 number to the carryover number from my 2019 return, the 2018 number recalculates to the correct number for 2018. If you did your 2018 and 2019 taxes using TT Home & Business you should be able to go back and find the 2018 and 2019 QBI carryover numbers. Putting in the correct 2019 number should adjust the 2018 number to the correct number -- I would check both numbers.
NOTE: I am not a CPA or tax professional so I am not attempting to give any tax advice.
