It’s because your WordPress theme or other plugin which is active, made a conflict with IgniteUp CSS styles. IgniteUp is dequeuing all enqueued stylesheets from any other sources to avoid any conflicts. But in some themes, they are using on-page or in-line styles that will not be removed. In those cases those can be caused for some conflicts or may completely ruin IgniteUp templates.
Try switching to one of WordPress default themes and check if your theme causes the conflict. If the issue still exists in WordPress default theme, it should be a plugin causing the problem. Then try deactivating active plugins one by one to find out which of your active plugins caused it.
Contact us if you finds out the conflicted theme or plugin (with the name and the URL to find the theme or plugin). Reporting us will help to improve IgniteUp to minimize conflicts as much as possible in the future.