Thank you again for your support. I figured it out myself in the meantime.
If anyone has the same problem, this is how the fade effect can be implemented:
In your home-slideshow.php file (Child Theme) replace class=”carousel slide” by class=”carousel fade”. Then in the stylesheet.css (Child Theme) add the following code:
.carousel.fade { opacity: 1; } .carousel.fade .item { transition: opacity ease-out .7s; left: 0; opacity: 0; /* hide all slides / top: 0; position: absolute; width: 100%; display: block; } .carousel.fade .item:first-child { top: auto; opacity: 1; / show first slide */ position: relative; } .carousel.fade .item.active { opacity: 1; }