Hide the hover + (plus symbol)

@therealdj Hi there!

Please try to add this code to Appearance -> Customizer -> CSS:

.gt3-photo-gallery-pro--isotope_gallery .hover-default .img-wrapper:after {
background: url(../../img/plus.00556b2f.svg) no-repeat 50%;
display: none;
}

Thank you for this very quick solution @kellyoswald! This is exactly what I wanted.