If you are referring to your basis from your 2023 Form 8606 line 14 then please see Why am I unable to report my 2023 for 8606 basis?
Please see How do I enter a backdoor Roth IRA conversion? for additional information.
I am not sure if the link you gave addresses my problem. The link explained that you are working on basis input for the filer. I do not have this issue.
I am able to input my basis (form 8606 line 14) from previous years. The Turbo tax software asked me this question. But it does not ask for my spouse's. So as a result, his form 8606 is wrong.
To clarify, your spouse has a Form 1099-R entered and you assigned the Form 1099-R to the spouse?
If your spouse is still not getting the "Any nondeductible Contributions to your IRA?" screen to enter the prior year basis then the issue from the Why am I unable to report my 2023 for 8606 basis? applies to your situation. Please sign up to receive updates on this issue.
This is when I report non-deductible IRA contribution we plan to make for 2024 before 4/15/2025. There is no 1099-R involved. Turbo tax asked our contribution individually, my basis from previous years, but did not ask my spouse's basis from previous years.
If your spouse does not get the question to enter her prior year basis then you will have to wait until the issue is resolved and sign up for the updates in Why am I unable to report my 2023 for 8606 basis?