After several searching in this form, I understand why my federal tax due jumped significantly. The cost basis showed zero on Form 1099-B. I went to and download my RSU transaction statement for 2023 which listed the #’s of shares sold with the sale price. I entered zero for Cost Basis but selected “The cost basis is incorrect or missing on my 1099-B”. On the next page, I just selected the first option of “I found my adjusted cost basis” and added the calculated amount of shares sold * sales price per sale. The Proceeds and Costs Basis are nearly the same (although some are off by a few amount).
