Hello

As the issue appears to be only present when you enable your modal extension, have you considered contacting the extension develop?

Ciarán

I make some test and find same behavior, basically if only one template (the homepage one ie) the modal effect works, I found these topics related

https://forum.joomla.org/viewtopic.php?t=951743
https://forum.joomla.org/viewtopic.php?t=955552

Not sure How I can find a solution here ?

Hello

That is rather strange. The plugin does not effect your header slideshow, however appears to effect your entire template menu assignment. Basically your default template style is been assigned to all pages with menu assignment of other template styles been ignored.

The issue is present regardless of what template is default (including default Joomla templates, Protostar etc.) so does not appear to be template related.

Ciarán

I send you the information by email

Hello

May I suggest sending temporary administration access to your Joomla installation to info@joomla51.com and we will examine this issue further. For our reference please paste a link to this post in your email.

Ciarán

Hello,

I use this plugin : JCKmodal

https://arkextensions.com/documentation/jck-editor/108-joomla-configuration-enabling-plug-ins
ti load this code

JHtml::_('behavior.framework');
JHTML::_('behavior.modal');

who enable the modal feature of joomla

but when enable it broke the "Header Image(s)" feature of your template...

I attach the plugin

Hello

By default the template does not include a popup library. We would recommend using one of the many extensions available to Joomla for this purpose (https://extensions.joomla.org/category/style-a-design/popups-a-iframes/).

You can't go wrong with the Regular Labs solution... https://extensions.joomla.org/extensions/extension/style-a-design/popups-a-iframes/modals/

Ciarán