Slider not working on subsite

I have a multisite and I am trying to use the same slider that I have working on my main site on a subsite, but for some reason it is not working on the subsite, it’s not visible at all (I am using different themes on the 2 sites).

All elements in the slider disappear when they are in the #carousel div, if I remove the #carousel I can see the content, but the images don’t load.

The slider is a Bootstrap slider and I added the same code on functions.php file on the theme that I am using on the subsite and on the one of the main site to add the function to create the shortcode that I am placing on the page Editor (I am using WPBakery Builder on both sites). And I also have the same file placed on both themes, under themes/**site-theme**/template-parts/carousel-slider-template.php

So even having the same settings on both themes, the subsite is not working, not sure why. Could you help me fix this?