Error in Software on Form 8960?

Hello!  I think there is a possible error in the software.

 

Facts:  

* Schedule C income + Rental income #1 + Rental loss #2 

* Rental income #1 and rental loss #2 are from short term rentals with material participation (nonpassive income)

 

Issue:

All three of these are going net to NIIT line 4a.  However, for line 4b only Schedule C income and rental income #1 are flowing through.  The loss is not going through from rental #2  (i.e. it is not netting with Schedule C and rental income #1).  

 

I made rental loss #2 income and it does flow through then.  Why is the program not netting the loss on 4b?  I read the IRS publication and it seems like it should flow through as well...