Form 8582 1a input with net section 1231 gain

In my K-1, I have a loss from box 2(Net rental real estate income(loss)) and a gain from box 10(Net section 1231 gain). When TurboTax generated Form 8582, it automatically put my net section 1231 gain into box 1a(Activities with net income). My understanding of section 1231 gain is that it's a capital gain of an investment which in my case is selling of a property.

 

Please help me to understand why TurboTax put a captial gain in Passive Activity Loss Limitations(Form 8582).

 

Thanks, Long