Investors & landlords

in my case, I've had my rental property for almost 20 years & I've never had to enter this that I'm aware of!

The form shows amounts for 2018 & 2019 in the Loss & QBI columns - I really don't know what to put!

Yes, I've had a passive loss carryover for years on this property.

How to I figure out what number should be put into this box?

under the Disallowed Passive Losses by Year & Type

Before 2018 - Operating Loss - Regular Tax -14,299 then QBI column is )

2018 Operating Loss is  -1865, then QBI column says -3965

2019 Operating Loss is -2100, then QBI column is blank & wants a number?

How do I calculate this?

Why didn't Turbo Tax do this for me?  It appears that it did it last year for 2018?