This answer applies to my situation too. I held some shares of Yahoo which I purchased in 2000 and than were subsequently converted into shares of ALTABA in 2017. Then the ALTABA liquidation began in 2019 and I started to receive distributions reported in box 9 of my 1099-DIVs for 2019 thru 2023. The final distribution occurred 2/17/20. I created a 1099-B entry using 2/17/23 as the sale date, the sum of all the distributions as the sales price, the date my YAHOO got converted to ALTABA as my purchase date, and my original YAHOO purchase as basis to record the long term loss. It's my understanding that TTAX would not have included any of the prior box (9) Cash liquidation distributions from my earlier 1099s as taxable income
