Thanks for letting me know.
Please change this previous code:
@media only screen and (max-width: 768px){
.single-product .carousel-area .owl-nav {
display: block !important;
}
}
to:
@media only screen and (max-width: 768px){
.carousel-area .productCarousel .owl-nav {
display: block !important;
}
}
Regards