Why defaults to1040-SR when DOB August 1955?

Turbo Tax has prepared our taxes on 1040-SR rather than the regular form 1040.

 

IRS Instructions say this is option for those who were born prior to 1 January 1955 --  But that is not us!

 

My spouse turned 65 in August, and I am some years away.

 

Why did Turbo Tax do this??