a) helps to list the page this is on for editing. I think its this one:
wsifront.class.php in this folder: plugins/wsi/wsi/front (if using the splash in front option as opposed to the splash after page load)
b) it does appear as I found in another post that mailchimp plugin adds to the issue. If you load mailchimp and this plugin, dropdown menus stop working out of the default dropdown wordpress structure. Disabling this one OR mailchimp resolve it. For now I disabled mailchimp cause I need this one more than the mail chimp plugin I’m using.
How do you code around this and other conflicts, no idea :/ Par for the course with wordpress plugins I guess.