Custom Post Types not shown on category archives

Hi everybody,

I am quite new to wordpress and facing a problem which drives me crazy:

I added a new custom Post type following this guide: https://codex.www.ads-software.com/Post_Types

So I added the category “einsatz”.

Additionaly I have a category which is called “einsatz” so that also a normal post and a page can be marked as “einsatz”.

The new post type works as expected. The only problem is that on my category page https://127.0.0.1/wp/category/einsatze/ the new post type is not displayed. Only “post” types are shown in the list which are tagged as “einsatz”.

I now tried to add this piece of code to category.php
$query = new WP_Query( array( 'post_type' => array( 'post', 'einsaetze') ) );

The result is, that everything which is a post or a einsatz is shown, regardless of the category.

Also this doesn’t work

$args = array(
	'tax_query' => array(
		'relation' => 'OR',
		array(
			'taxonomy' => 'category',
			'field' => 'slug',
			'terms' => array( 'einsatze' )
		),
		'post_type' => array(
			'post', 'einsaetze')
	)
);
$query = new WP_Query( $args );

and there is an additional problem: I need this in a more generic way. So my script has to know which category is called and display everything within thos category.

I hope somebody can help me.