After I completed and saved my 2019 Amended tax return in TT, re-opening my 2020 return seems to be treated as new.

After I completed my 2019 Amended tax return in TT, I attempted to re-open my 2020 return, but the 2020 TT opened asked me if I wanted to start to a return as if new. Why is this if I had previously partially or completed a 2020 return? It also asked me to select from one of two options of the 2019 return.