@sohayda
the Turbotax support for 1099-K seems troublesome.
the simplest way to do this (and the way recommended by IRS) is:
enter 1099-K value on Schedule 1 line 8z
enter 1099-K value - <amount of gain on personal items> on Schedule 1 line 24z
on both lines, Description is : "Form(s) 1099-K personal items sold at a loss."
OR
if you want to use Form 8949 you can do that directly treating it as a stock, and not using the 1099-K feature.
Enter a consolidated line on Form 8949 Use Box C or F since you don't have a 1099-B
Loss on Personal Items is not deductible so you have to enter an adjustment to cancel the loss,
the adjustment is in Col g. the adjustment code (Col f) is "L"
description: "1099-K personal items "
enter another consolidated line for items sold at a gain.
Gain on Personal Items is a taxable gain.
you can also adjust for expenses of sale. adjustment code is "E" or "LE".
The proceeds subtotals should add up to your 1099-K
