I can't express my gratitude for your patience and detailed answer! @JamesG1
I followed your answer step by step. I deleted all my 1099-Ks. I added one 1099-K and then filled out the corresponding Schedule D worksheet with matching numbers. Then, I added the other 1099-K and filled out its corresponding Schedule D worksheet.
I did this process for at least 5 times. Sadly, Turbotax still has my schedule D worksheets entangled every time and doesn't allow me to e-file. The problematic Schedule D is always associated with eBay's 1099-K (even when I entered eBay's 1099-K first followed by its worksheet).
