Inline Variant Slots: template not updating when changes made

For various reason I have had to change the template use to populate an inline slot. The changes was small - the addition of a wrapping <p> tag so that the content would pick up styles associated with it. Now when I add content via the inline template it picks up the template changes but inline templates previously in the content item remain unchanged.

Is this expected? Do I have to manually re-add the existing inline slots in order to pick up the change or should this happen automatically

Any help would be greatly appreciated