No income. Why return third stimulus payment?

I am amending 2021 1040 with TurboTax desktop.  I originally received the third stimulus of $1,400. 

 

In both original filing and amended, I had zero income from all sources.  My original AGI was 0 and my amended AGI is negative $23,000.  I'm even carrying a capital loss, and had no capital gains whatsoever. 

 

With amendment, TurboTax concludes that I must return the $1,400 stimulus!

 

Why? What am I doing wrong?