Page template not displayed in the list of template on pages

Hi !

I’m working on a new Dawn theme (Dawn version 7.0.1)

The actuel published theme is a Debut version 11.3.1
When I create a new page template (contact or FAQ or whatever) on front editor

I can’t see it form page back editor in the list of template to attribute to

Support told me that because I’m not using 2.0 but I did, I’m actually working on the Dawn version.

Should I publish my 7.01 version before ?

Could you please help me ?