galaxx Hi. I do agree it's a jQuery conflict, from my understanding there is a newer bootstrap library used which is using a different version of one function in result, this function instead of just slide the content left-right it also changes the height of the sliding bar to 0px and moves the content in it to top. My css will lock those 2 values so there will be no need to go back to the old bootstrap which may be needed in a different place.
So once again, a css fix:
.main-image + div { height: 100px !important; }
.main-image + div > .additional-images { margin-top: 0 !important; }
unfortunately I do not know this template, so can't tell for sure where to add it. Maybe tay have prepared a separate css file for overrides called for example custom.css or override.css, if not than probably there is a field in template's settings for custom css.