eFile Rejection: TurboTax says return transmitted so can't resubmit

Hi, I submitted my parent's tax return and it was rejected with error message 031 (non matching prior year AGI). I obtained IRS transcript and confirmed I used the correct AGI. However, the IRS transcript showed a "computer" amount that was $1 less than the AGI they filed, so I resubmitted the return using that AGI thinking maybe a rounding issue caused the return to be rejected. I got another rejection email, but TurboTax now says the return was "transmitted" and will not give me the option to resubmit again. I was going to try submitting AGI of 0 to see if that works. As background, this is the first year eFiling their return (have filed paper copies in past). Also, my father passed away in 2019 and the return reflects he is deceased. Their filing status has always been married filing joint. I want to eFile for purposes of the stimulus payments. Please advise. Thanks.