@frankyw these warning were superficial and have been resolved. We hope you’ll reconsider using the plugin and updating your review accordingly. Thank you for bringing it to our attention.
@frankyw sorry for the late reply. We will look in to this and get the plugin updated.
This site is hosted with WP Engine (which caching has caused issues with other plugins in the past). Is there a known issue between this plugin and WP Engine? I’ve excluded cache entirely on these pages but the issue still persists.