The arrows are working fine on your shared site as on our demo site here https://jevelin.shufflehound.com/project/wind-at-white-castle/

If you want to just swap the postilion of arrows then you can do so by adding the following CSS code in the Custom CSS code option of your theme on the below path.

Admin Area -> Appearance -> Theme Settings -> Custom Code -> CSS Code

.sh-portfolio-single-buttons a.sh-page-switcher-button:first-child {
    float: right;
    margin-left: 15px;
}

.sh-portfolio-single-buttons {
    float: left;
}

.sh-portfolio-single-slider .sh-portfolio-single-title{
    clear:both;
    float: none;
}