From my experience, drag tab element in. Delete all but first pane. In the first pane add a div, the give it a class. Add your content inside the div.
When add another tab, don’t copy the first. Add a new one, if the div from one shows, delete it and add a new div, give it a different class. Repeat this for new tabs.
This is just my experience, others in the community may have a better solution. Hope that helps.