The creation of e-mails in the context of interactions and segments is not identical. For interactions, the field "Description" is used to create the email subject, whereas the field "Subject" is used when logging segments.
Therefore, when creating an interaction, the content of the field "Description" must be transferred to the field "Subject" (table 5077 - function "FinishWizard"). By displaying the field "Subject" in the Interaction Wizard, it would immediately be clear what the field is used for and would lead to less irritation. Perhaps also including visibility/editability control based on the selected interaction template.