Custom Post Types don't appear in Archive

Hello guys,

I’ve registered a Custom Post Type, and I made avaliable for it the support for post_tags.

'taxonomies' => array( 'location', 'propertytype', 'propertyfeatures', 'post_tag')

I can fill in the tags, check them out as admin, but when I go to a tag archive page, it will only show the tags assigned to typical posts, even if in the tag cloud the “new” tags for Custom Posts are showing up.

If clicked, they’ll go to an empty archive, with the correct URL, however.

Do you know what could I have missed?

Many thanks