Retirement tax questions

I am confident there's an error in the 2025 TurboTax Deluxe desktop software:

- I entered two 1099-R forms, one for pension distribution (all taxable) and a second form for a direct rollover from a 401(k) to an IRA (box 7 code G, non-taxable).

- the second 1099-R also reported a direct rollover from the same IRA into a Roth IRA and correctly reported that amount in box 2a (taxable).

- TurboTax included the pension distribution on 1040 line 5b (taxable amount) from the first 1099-R, but did not add the taxable amount from box 2a on the second 1099-R.

 

This is a serious problem. I've already submitted (filed) my taxes and now must amend the return, but I can't find a way to override line 5a on form 1040 with the correct total. What should I do?