Installed but does not appear

Yes, i haven't pressed the accept button so i can check that plugin is working.
At the moment i'm looking what is on protostar that in the custom templates is not there so the plugin works properly.

Comparing headers there is a difference in the way of calling stylesheets and scripts.
I'll try from there if something

At the moment i did a patch:

Took the javascript from the protostar rendered and copied it into a js file. I added into the loads and worked. The only things i need to do that are required is translate the strings.

I know that IS NOT THE IDEAL SOLUTION however it proofs that somewhere on the custom templates is not allowing to parse the javascript from the plugin.

So this issue stays on stand by while i figure out how to parse the javascript from the plugin into a custom template.

I think i found the answer.

Missing JQuery .
I removed the Joomla's core for a conflict, but i forgot to set up an External JQuery as replacement.

So I disabled the patch and now it works.

I have to test on the other template to see if it works

happy to see that you have found where is the problem

Yes, and might sound a bit silly, but if I haven't imported the Javascript and tested as separate entity, I could not find where it was.

In the end I found after trying to import headers lines and I saw errors asking me for jquery. I tried the external Library and voila.

I have pending the test on my design, so I can confirm the point