Show map field in related post

I have connected 2 custom post types (events, map) to the MB_Relationships_API After that I created a view for the CPT events detail view and for maps also.

Now I want to show the venue in the detailed view of the event. The field longitude and latitude is displayed without problems, the corresponding map unfortunately not.

No errors are shown in the console. Here is my code in the detail view of events:

<h2>
    {{ post.title }}
</h2>

<div class"veranstaltung-datum">
    {{ post.date | date( 'j. F, Y H:i' ) }} Uhr
</div>

<div class"veranstaltung-text">
    {{ post.wysiwyg_veranstaltung }}
</div>

<div class"veranstaltung-karte">
    {% for post in relationships.veranstaltung_to_karte.from %}
        {{ post.osm_karte.latitude }},{{ post.osm_karte.longitude }}
        {{ post.osm_karte.rendered }}
    {% endfor %}
</div>

Screenshot detail view events: https://prnt.sc/vl8cka
Screenshot detail view maps: https://prnt.sc/vl8d0i

What is it that I am doing wrong?