side panel not working

I have just changed the template to Casiopeia. It is the default J4 template.
And still no change, so I do not think it is my template.
But I am no expert.
Take a look.
I will have to change it back tomorrow.

I can see that in your page jquery loaded not by my map (added script) because on page you got error JQuery not defined and many other bad warnings.
And I can see it loaded after my libraries by the other extension.

Check what you install (or port) from j3. Disable the other extensions, which is not from basic joomla installation. We need to find out what it cause.

I have pure j4 installation and my extension installed. And in map details loaded jquery.
And it works.

I can see wrong path in your page

<script src="//media/vendor/jquery/js/jquery.min.js?48030473fac6bff6c190f2c032da08f3"></script>

TWO slashes

OK, so I changed the path in the advanced options of the map from
/media/vendor/jquery/js/jquery.min.js
to
media/vendor/jquery/js/jquery.min.js
and now everything is working.
You still thing it is problem of my config? I will check the rest of my installations, but I deleted all j3 components.
I have your ZH Template Map Full Screen version 2.22.1.1, but it is not enabled. Is there any new template available?