Remove (incorrectly included) Roth IRA excess contribution from previous year

I only caught this because the same thing is happening again in 2022, but on my 2021 return Turbotax brought over my excess Roth IRA contribution from 2020 (line 24 of form 5329), populated line 18 of Form 5329 with it, and charged 6% tax on it.  The problem is I have no idea where it got this excess contribution from 2020. My only guess is that in 2020 I started my taxes in Turbotax, but I ultimately filed using another company.  The 2020 return actually filed with the IRS has no excess Roth IRA contribution (and no Form 5329), which is correct given that I contributed the 6k limit and was under the MAGI limit that year.

That excess contribution carries over every year, so I'm currently trying to file an amended return for 2021 so that I can also use Turbotax to file in 2022.  Does anyone know how to manually update line 18 on form 5329 so that I can amend my 2021 return to match what was actually filed in 2020 (zero excess contribution)?  I'm hoping that fixing this will also fix my 2022 return (currently in progress), which has the same excess contribution carried over from 2021.