Thank you – this works wonderfully – however as you already write not for Gridlayout.

And especially in this context a grid layout would be exactly what is often desired.
So maybe Günter can find in future releases the option to have :

( and on all other elements that have the option to choose Which Entries are displayed? – Select which entries should be displayed by selecting a taxonomy )

i do not know anything about your code provided by your third party service ( even if it is a javascript code – if it is only a style then we had to do it a different way )
but if it is a script code- then that code replaces the line:
// replace that line here by your script code – so it is between the script tags

see: https://webers-testseite.de/sticky-sidebar/
see usage in a real environment: https://clean.webers-testseite.de/datenschutz/
______
or for sticky elements : https://webers-testseite.de/sticky-elements/

in the lang files of formal : de_DE_formal.po it is correct : “Der letzte Kommentar muss genehmigt werden.”
( i.e. when using the formal form of address “SIE” )

and indeed on the informal de_DE.po it is incorrect: “Das letzte Kommentar muss genehmigt werden.”

So you can either switch to the formal Version of the lang file ( on dashboard – settings – site language )

Or you can edit that lang file ( using poedit ) and have your own child-theme langfile for that:
(edited Versions of both files .po and .mo files to upload in subfolder of your child-theme: lang )

function overwrite_language_file_child_theme() {
    $lang = get_stylesheet_directory().'/lang';
    return $lang;
}
add_filter('ava_theme_textdomain_path', 'overwrite_language_file_child_theme');

or – quick and relative dirty way:
( in child-theme functions.php )

function my_text_strings( $translated_text, $text, $domain ){
  switch ( $translated_text ){
    case 'The last comment needs to be approved.' : $translated_text = __( 'Der letzte Kommentar muss genehmigt werden.', $domain ); break;
    // case 'Das letzte Kommentar muss genehmigt werden.' : $translated_text = __( 'Der letzte Kommentar muss genehmigt werden.', $domain ); break;
  }
  return $translated_text;
}
add_filter('gettext', 'my_text_strings', 20, 3);

( if first case does not work uncomment the second case in that code and remove the first case )

or use a plugin to correct that wrong translation

although I think that it is not generally to set, because you often want to add explanatory / introductory words to the external links (videos, audios …). And therefore a call to the post makes sense.

but wouldn’t only a change in the loop-index.php be necessary?
Within a blog, the $pf_link is also checked for post-format, so that here directly from the blog the link does not go to the post but to the link.
so set the link for : ($post_format !== 'standard') to the postformat link ($pf_link) in general ?

this might help –
that snippet comes to your child-theme functions.php:

function your_custom_script(){
?>
<script>
	// replace that line here by your script code
</script>
<?php
}
add_action('wp_head', 'your_custom_script');

but How it is ultimately set also depends on whether it needs any requirements. E.g. the user script needs jQuery – then this must be loaded first before your user script is inserted.

depends on where the text-block is? – because f.e. color-sections got a min-height setting of 100px

but why does it break the board soft ( this code inside codetag) but on my wordpress installation inside child-theme functions.php not ?

Bei iPad Quer hast du dann die Grid-Zellen nebeneinander?
Das Problem bei dem Konstrukt ist ja das der Content in der anderen Grid-Zelle die Höhe bestimmen muß – ansonsten würde der in das Overflow geraten, oder abgeschnitten werden.
Daher funktioniert das nur entweder wenn wir im Responsiven Fall sind ( also jede Grid-Zelle die 100% füllt) oder in seltenen Fällen der Content in der anderen Zelle sehr klein ist, sodaß man die Zelle mit dem Hintergrund bestimmen lassen kann wie hoch die Grid-Row ist.

Schau dir nochmal die Beispielseite an. Unten ist der o.a. Fall : wenig Content
bei einer 1/2 Grid-Cell hast du dann auch nur die Halbe Höhe um ein “responsives” Verhalten zu erzwingen.
Mit fixed geht dies nich ( und schon garnicht mit parallax ) Fixierte Elemente befinden sich quasi nicht im ElternContainer – daher ist die basis eines
background-attachment : fixed die 100% screenweite.

Für den Fall Grid-Cells nebeneinander habe ich eine weitere Klasse gesetzt:

_____________

With iPad landscape you have the grid cells next to each other?
The problem with the construct is that the content in the other grid cell must determine the height – otherwise it would get into the overflow, or be cut off.
Therefore this only works if we are in the responsive case (i.e. every grid cell fills 100%) or in rare cases the content in the other cell is very small, so you can let the cell with the background determine how high the grid row is.

Have a look at the example page again. Below is the above case : little content
with a 1/2 grid-cell you have only half the height to force a “responsive” behavior.
With fixed this is not possible ( and certainly not with parallax ) Fixed elements are not in the parent container – therefore the base of a
background-attachment : fixed is the 100% screen width.

For the case of grid-cells next to each other I set another class:

@media only screen and (min-width: 990px) {
  #top .flex_cell.responsives-verhalten.nebeneinander  {
    background-attachment: scroll;
    padding: 0 !important
  }

  #top .flex_cell.responsives-verhalten.nebeneinander .flex_cell_inner {
    height: calc(56.25vw / 2) !important;
  }
}

_____________

leider ist deine Seite ja nicht online erreichbar, es wird nur eine “Coming Soon” Seite angezeigt.
Wenn du allerdings auf diese Demoseite (Link) abzielst, dann ist es auch dort nicht so, dass die Bilder responsive sein können. Der Grund ist, dass es eben keine Bilder sondern Hintergrundbilder sind.
( PS beim Einsetzen der Hintergrund-Bilder darauf achten, dass du auch die Vollauflösung einsetzt und kein 300px Bild )

Man könnte das zwar erreichen ( am leichtesten dadurch, das zunächst alle Hintergrundbilder die gleichen Dimensionen – zumindest aber die gleichen Seitenverhältnisse aufweisen). Den Hintergrund dann auf Scroll zusetzen ist ratsam wie es Ismael vorgeschlagen hat, denn ein Cover Bild müsste ja die gesamte Screenhöhe ( nicht die Containerhöhe ) abdecken.

Ein Hintergrundbild auf cover gesetzt ist dann “responsiv”, wenn die Containerhöhe mit dem Seitenverhältnis des Hintergrund-Bildes correliert.
Auf meiner Beispielseite haben die Bilder ein 16/9 Seitenverhältnis ( 1920/1080) haben also bei voller Breite (100vw) eine Höhe von 56.25vw !

_________

unfortunately your page is not available online, only a “Coming Soon” page is displayed.
However, if you point at this demo page (Link) , then it is also not the case that the images can be responsive. The reason is that they are not images but background images.
( PS when inserting the background images make sure that you also use the full resolution and not a 300px image ).

You could achieve this (the easiest way is, that all background images have the same dimensions – but at least the same aspect ratio). Setting the background to scroll is advisable as Ismael suggested, because a cover image would have to cover the whole screen height (not the container height).

A background image set to cover is “responsive” if the container height correlates with the aspect ratio of the background image.
On my example page the images have a 16/9 aspect ratio ( 1920/1080 ) so at full width ( 100vw ) they have a height of 56.25vw !

see ( with 989px breakpoint):
https://webers-testseite.de/gridrow-layout-with-fixed-bg/

and what do you expect it should look like
open f.e. :

https://www.stilecatalini.it/portfolio-articoli/ventuno-sport-fisherman/

and compare the behavior with that of the light box. Where is a difference (except the height width of the page) between them that bothers you?