Including others post width pre_get_posts and meta_query on archive page tag

I have a problem with a pre_get_pots function for the archive page tag (is_tag()).
I want to add some posts to diplay on the archive page tag, with meta_query, corresponding to a meta field (of post).

Here is my function

The problem is that the posts are only displayed in the following case: when the tags and the meta field are set.

Thank in advance.