Did you check box D on the 6781? if so, you told the IRS that your 1256 losses, subject to the various limitations would be carried back to the third prior year.
here are the rules
Box D. Net Section 1256 Contracts
Loss Election
If you have a net section 1256 contracts loss for 2023, you can elect to carry it back 3 years (by checking box D on form 6781). Your net section 1256 contracts loss is the smaller of:
• The excess of your losses from section 1256 contracts over the total of (a) your gains from section 1256
contracts plus (b) $3,000 ($1,500 if married filing separately), or
• The total you would figure as your short-term and long-term capital loss carryovers to 2024 if line 6 of Form 6781 were zero. Use a separate Schedule D (Form 1040) and Capital Loss Carryover Worksheet (in Pub. 550) to figure this amount.
The amount you can carry back to any prior year is limited to the smaller of:
• The gain, if any, that you would report on line 16 of Schedule D (Form 1040) for that carryback year if only gains and losses from section 1256 contracts were taken into account; or
• The gain, if any, reported on line 16 of Schedule D (Form 1040) for that carryback year. The amounts just described are figured prior to any carryback from the loss year. Also, the carryback is allowed
only to the extent it doesn’t increase or produce a net operating loss for the carryback year. The loss is carried to the earliest year first.
Make the election by checking box D and entering the amount to be carried back on line 6. To carry your loss back, file Form 1045, Application for Tentative Refund, or an amended return. Attach an amended Form 6781 and an amended Schedule D (Form 1040) for the applicable years.
On the amended Forms 6781 for the years to which the loss is carried back, report the carryback on line 1 of that year’s amended Form 6781. Enter “Net section 1256 contracts loss carried back from” and the tax year in column (a), and enter the amount of the loss carried back in column (b).
