Schedule D has populated 1a & 8a

I am trying to finish my 2018 form 1040, having extended.

 

I have many entries in Forms 8949, as expected. All were imported from my brokerages except for one hedge fund which I had to enter manually.

 

And yet on my Schedule D, lines 1a and 8a are populated. I don't recognize the numbers in those lines, but I thought that if Forms 8949 were completed, lines 1a and 8a should be blank.

 

TT (desktop) will not show me Data Sources for those lines. The right-click menu is completely disabled except for the "About" menu item.

 

Can anyone please explain why I have numbers in Schedule D lines 1a & 8a despite having Forms 8949 full of data?