Given the symptoms your describing, and how uncommon they are for NG users, it seems fairly clear you’re experience a theme or plugin conflict. While that’s quite rare these days, it can still be hard to ensure compatibility with all of tens of thousands of plugins and themes out there.
If you feel motivated enough to troubleshoot, the way to find a conflict is to:
1) Deactivate other plugins one by one OR deactivate all plugins and reactivate one by one. If you do this, you’ll find one particular plugin that triggers the issue.
2) If you go through #2 and don’t find any issues, it’s likely the theme. You can test by changing themes, but most users prefer not to do that. Alternatively, if you have a second WP instance, you can test there. I’d even say that if you go through the process for #1 and don’t find an issue, you can just let us know what theme you’re using, and we’ll test ourselves.
Otherwise, I assume you’ll move on. We appreciate you giving the plugin a try. Sorry it’s not working for you. We hope you find a great solution that does.