Yes, it is a software bug. The return of the excess contribution is reported on your 2019 taxes due in April of 2020. Do not try to add it as 2018 income. The suggested workaround at this point, according to the folks I've corresponded that work for Intuit, is to file on paper instead of e-filing. Let me know if that doesn't work, i.e. if TurboTax still refuses to move forward, and we can try another option. You are not alone!
