I am sure this is due to your markup and the hang state on the .gallery-category:
.gallery-category:hover {
color: white;
cursor: pointer;
}
iOS does not support: hover the cursor in the usual way, because there is no way to detect a hover state without a mouse. It usually sorts itself by its direct state: hover, but I assume that your markup is a bit complicated (and there is a hover state on the parent element there), which causes it to break.
,
.gallery-category a:hover {...
( )