I just ran into the same problem. If the answer is as simple as this, why does Turbo Tax allow the return to be efiled? They should simply say that you can't efile a return for a deceased taxpayer.
Plus it says elsewhere in this community (can't figure out how to link here) that a return for a decease taxpayer can be efiled.
So I am in the same situation as the OP. The return was rejected even though I put in the correct AGI.
Although I notice that the OP said there was no place to enter the spouse's information. That makes sense since they filed jointly in 2018. My wife and I filed married filing separately in 2018 and I'm filing jointly for 2019. Turbo tax did ask for each of our 2018 AGIs separately.
