I’m sorry for the delay.
Yes, I closed the site…
I found additional problem conditions: it is played if the “Tabs” are inside the “Row Layout”.
The “kadence” blocks are used. Here is a ready-made minimal html fragment (preview):
<!-- wp:kadence/column {"borderWidth":["","","",""],"uniqueID":"_6bd911-aa","borderStyle":[{"top":["","",""],"right":["","",""],"bottom":["","",""],"left":["","",""],"unit":"px"}]} -->
<div class="wp-block-kadence-column kadence-column_6bd911-aa"><div class="kt-inside-inner-col"><!-- wp:kadence/tabs {"uniqueID":"_640557-b8","layout":"vtabs"} -->
<div class="wp-block-kadence-tabs alignnone"><div class="kt-tabs-wrap kt-tabs-id_640557-b8 kt-tabs-has-3-tabs kt-active-tab-1 kt-tabs-layout-vtabs kt-tabs-tablet-layout-inherit kt-tabs-mobile-layout-inherit kt-tab-alignment-left "><ul class="kt-tabs-title-list"><li id="tab-tab1" class="kt-title-item kt-title-item-1 kt-tabs-svg-show-always kt-tabs-icon-side-right kt-tab-title-active"><a href="#tab-tab1" data-tab="1" class="kt-tab-title kt-tab-title-1 "><span class="kt-title-text">Tab 1</span></a></li><li id="tab-tab2" class="kt-title-item kt-title-item-2 kt-tabs-svg-show-always kt-tabs-icon-side-right kt-tab-title-inactive"><a href="#tab-tab2" data-tab="2" class="kt-tab-title kt-tab-title-2 "><span class="kt-title-text">Tab 2</span></a></li><li id="tab-tab3" class="kt-title-item kt-title-item-3 kt-tabs-svg-show-always kt-tabs-icon-side-right kt-tab-title-inactive"><a href="#tab-tab3" data-tab="3" class="kt-tab-title kt-tab-title-3 "><span class="kt-title-text">Tab 3</span></a></li></ul><div class="kt-tabs-content-wrap"><!-- wp:kadence/tab {"uniqueID":"_517054-7a"} -->
<div class="wp-block-kadence-tab kt-tab-inner-content kt-inner-tab-1 kt-inner-tab_517054-7a"><div class="kt-tab-inner-content-inner"></div></div>
<!-- /wp:kadence/tab -->
<!-- wp:kadence/tab {"id":2,"uniqueID":"_feb35b-ac"} -->
<div class="wp-block-kadence-tab kt-tab-inner-content kt-inner-tab-2 kt-inner-tab_feb35b-ac"><div class="kt-tab-inner-content-inner"></div></div>
<!-- /wp:kadence/tab -->
<!-- wp:kadence/tab {"id":3,"uniqueID":"_dcd2dc-dd"} -->
<div class="wp-block-kadence-tab kt-tab-inner-content kt-inner-tab-3 kt-inner-tab_dcd2dc-dd"><div class="kt-tab-inner-content-inner"></div></div>
<!-- /wp:kadence/tab --></div></div></div>
<!-- /wp:kadence/tabs --></div></div>
<!-- /wp:kadence/column -->