Ding, ding, ding!  Lisa get's the prize.

Filing status IS one of the things that has to be amended on a paper return:

https://www.irs.gov/filing/amended-return-frequently-asked-questions

(As of 2/11/2021) Amended Returns must be filed by Paper for the following reasons:

1. Only Tax Year 2019 and 2020 1040 and 1040-SR returns can be amended electronically at this time. Amended Returns for any other tax years or tax types must be filed by paper.
2. There must be a record of an "original" electronically filed return for Tax Year 2019 or Tax Year 2020. If the original Tax Year 2019 or Tax Year 2020 return was filed by paper, it must be amended by paper.
3. If the Primary Social Security Number is different from the one provided on the Original Return, then the Amended Return must be filed by paper.
4. If the Spouse's Social Security Number (if applicable) is different from the one provided on the Original Return, then the Amended Return must be filed by paper.
5. If the Filing Status differs from the Filing Status on the Original Return, then the Amended Return must be filed by paper.