I had this same issue with 2019 ProSeries!!!

Deceased passed in March 2020, we went to file 2019 return. We had to mail it in because I had this SAME ERROR! We mailed in the Form 1310 to the IRS with the 2019 Return, so there is no reason I shouldn't be able to (in 2020 ProSeries) select B (Part 1) and also B1 (If box B is check the court certificate of appointment has been sent to the IRS). File it and be done.

I am very upset that they haven't fixed it - how is this possible???

The estate is wanting to close out their bank account and distribute proceeds and cannot do that until the refund is processed. 

How is it I can file the 1041 that owes money electronically without an issue, yet the refund is causing a error that does not allow it to proceed!.

I will be calling tech support in the morning to demand a fix for this nonsense!.