Debugged this some more. Regular rental property losses are not propagated to QBI (checked for TT 2018-22) - i.e. line 4a in QBID Smart Worksheet is zero. Soon as you switch to mixed rental use (personal use days > 10%/14d) then TT 2020-22 do propagate it to 4a, but TT 2018-19 do not. And once it's propagated it's both tracked as QBLC (loss carryforward) and is deducted from active income. Former is expected, latter is not.
Can't be a bug if it's in three versions of TT. Must be some condition that lets you deduct mix-used rental losses through QBI, while also accruing them as QBLC. One thing I noticed is that when I set "Days of personal use" TT checks SchE line G "Other passive exceptions", which is otherwise clear, but just checking it alone doesn't enact this propagation.
Hope someone knows what's driving this logic in SchE QBID Smart Worksheet for TT 2020-22.
Best, MM
