Check Setting->Type, if Type “Inline Link”->Smart Selector
Compare with the HTML Element by hitting F12 button -> find the Element.
If you can't find the HTML, you should choose the Position again.
* Note: Please publish the App and re-select the Position after you changed the theme.
Solution #2: In the Campaigns->Advanced
If you enable the Smart Selector for each campaign, you will need to check and choose the position for the campaign.