I have never even tried to transfer Org files to 1040 files.

I transfer 2020 1040 to 2021Org for the organizers,

Then I re-transfer 2020 1040 to 2021 1040, as the returns are ready to be prepared.

Never actually even thought about the possibility of the org to 1040 transfer, but the other way has been working for me for 20+years. (including this year.)