The infobox header of the English Wikipedia's Template:Infobox anthem seems to malfunction in Safari, being incorrectly positioned upon page load and moving down the screen as the audio plays. Confirmed here. This doesn't happen with Template:Infobox song, which uses the same helper template for the audio and the same helper template to generate the infobox.
Steps to reproduce
- Open a Wikipedia article containing the infobox, such as "The Internationale", in Safari on macOS.
- The infobox header will be at the bottom of the infobox. Press play. The infobox header will start moving down the page.