add insertBefore=null so the content of the existing modal isn't replaced (see in-element docs), make backdrop and modal z-index the same, so new modals can be shown over existing modals

Author: karel kremer

addon/components/au-modal.gjs

@@ -85,7 +85,7 @@ export default class AuModal extends Component {
 
   <template>
     {{#if @modalOpen}}
-      {{#in-element this.destinationElement}}
+      {{#in-element this.destinationElement insertBefore=null}}
         <div class="au-c-modal-backdrop {{if @modalOpen 'is-visible'}}"></div>
         <div
           id="{{@id}}"

styles/components/_c-modal.scss

@@ -6,7 +6,7 @@
    ========================================================================== */
 
 $au-modal-z-index: 9999 !default;
-$au-modal-backdrop-z-index: 9998 !default;
+$au-modal-backdrop-z-index: 9999 !default;
 
 /* Component
   ========================================================================== */