This is an update to let you know that I've added just a couple lines of CSS to fix the issue with the lightbox caption delay/lag issue. The lines are added at the end of the CSS in the original post. They are:
transition: opacity 0.1s ease-out;
.gallery-lightbox-item[data-in=false] .gallery-item-description {
opacity: 0;
}
Special note to those who mentioned the issue: @kinapark , @IvanOB , @ed.design , @JohnS123
