Doh! I just realized this bug occurred because my WP site was on our Intranet, and IE11 by default was checked to show intranet sites in compatibility mode. It’s not an issue.
Bump. Surely others are using this plugin with Lifestyle Pro? As best I can tell it appears that the theme’s style.css is overriding several styles in the plugin’s css. I tried adding !important to several styles with no results.