Section 1341 Repayment "How to"

Quick question with explanation at the end. In publication 525 when calculating the credit for repaid amount from prior year the wording used through out is "figure your tax". Does this mean line 16 tax or line 24 total tax?

I have a client that received 31K in disability payments in 2021. this caused him to have to pay an excess premium tax credit of 4k in 2021. He had to pay that back because he obtained social security disability for that year paid in 2022. If recalculate the 2021 return without the repayment amount his tax is reduced by 3738. the Schedule 2 adjustment on line 17 is another 2800. should I apply the difference in tax of 3738 or the total tax of 6538 for the year 2022?

I am assuming the latter but I can't find anything confirming that position. Thank you for any information provided.

"The answer, my friend, is written in" the Code Section in the title of your post.

26 U.S. Code § 1341 - Computation of tax where taxpayer restores substantial amount held under claim of right
(a) General rule
If—
(1) an item was included in gross income for a prior taxable year (or years) because it appeared that the taxpayer had an unrestricted right to such item;
(2) a deduction is allowable for the taxable year because it was established after the close of such prior taxable year (or years) that the taxpayer did not have an unrestricted right to such item or to a portion of such item; and
(3) the amount of such deduction exceeds $3,000,
then the tax imposed by this chapter for the taxable year shall be the lesser of the following:
(4) the tax for the taxable year computed with such deduction; or
(5) an amount equal to—
(A) the tax for the taxable year computed without such deduction, minus
(B) the decrease in tax under this chapter (or the corresponding provisions of prior revenue laws) for the prior taxable year (or years) which would result solely from the exclusion of such item (or portion thereof) from gross income for such prior taxable year (or years).

And the related reg. has examples.

thank you for the response.