The current music website for the past several years has had issues with Safari. On iOS, all browsers (including Chrome) use the Safari webview, which is why you're getting the error there too.
If you look up music on your iPad or iPhone frequently, I'd recommend installing the Church's official "Sacred Music" app. In the app, there's a menu in the top right that allows you to switch the language to see American Sign Language content.
Alternatively, you can use the new music website, which is in the process of being rolled out. Here's a direct link to the landing page for ASL music content:
https://www.churchofjesuschrist.org/media/music?lang=ase