Not displaying tab titles

Hello, i must say this plugin is amazing and comes very handy. However I’m having a little issue with it, the tabs title ain’t showing. I think its from the theme as i deactivated all my plugins and it still wasn’t showing up. This is the 1st time am having an issue with this plugin as I’ve used it on some of my sites. Can someone please help out? Thanks.

https://wordpress.org/plugins/tabby-responsive-tabs/