Travel Authorization - Fluid User Interface

The expense type selected on this page "Travel Authorization - Fluid User Interface" is displaying by default on the first line when creating a TA, how to properly configured this page so that at TA creation the Expense Type listed on this page is no longer displaying as the default on the first line of the TA or is this required because Expense Type on TA is a required field? Also, why other fields are also required and these are all blank by default at TA creation?

Note: For illustration purposes Image extracted from Replication_Steps_for_Defect_32806464.pdf:

Thank you for your valuable feedback.