It took a while to find, but I resolved the problem by modifying the “portfolio-slideshow/inc/shortcode.php” file in the plugin editor. Deep into the file, under ‘case “openurl”, I changed '" target="_blank"' to '" target="_self"'. Now slide links within the site open in the same page, instead of new tab.
This might only be a temporary fix, because any subsequent plugin updates will overwrite the change.
I figured it out. I had added code to the caption of the first slide in an effort to italicize the text. But closed some of the changes with an incorrect ‘<em/>’. I don’t know exactly how, but that’s all it took to short circuit the ‘active slide’ and subsequent pager image opacity.
