Okay I have figured it out myself via this post:
Blockquote If your photos have either of these two EXIF fields set and you want a strict 1:1 relationship between items and photos then you can make a copy of the default item template, add the respective EXIF date field to it and then set this template as the default item template.
Why do my imported photos have no metadata.
I had to create a new Generic template with a property for “DateTimeOriginal”
