Hello, freichorn.
That's definitely unexpected behavior to see your Beats not working with an iPad and an iPhone, but work with your Mac. We're glad to look into this further with you. Let's begin by going through the steps in this article: If your headphones don't work with your iPhone, iPad, or iPod touch - Apple Support. It advises:
"Check for debris, damage, or loose connections
- Check for debris in the headphone port on your iPhone, iPad or iPod touch.
- Check your headphone cable, connector, remote, and earbuds for damage, like wear or breakage.
- Look for debris on the meshes in each earbud. To remove debris, gently brush all openings with a small, soft-bristled brush that's clean and dry.
- Firmly plug your headphones back in. If your iOS device has a case, remove the case to get a firm connection.
If your headphones still aren't working, follow the steps below for your issue.

If you can't hear any sound or if only one side of your headphones works
- Adjust the volume with the volume buttons on your iOS device or use the Volume slider in Control Center on your iPhone or iPad.
- To see if you need a replacement, try a second pair of headphones. If the second pair works, contact the manufacturer of the initial pair and ask if you need a replacement. If the second pair doesn't work, contact Apple Support."
Let us know if we can help with anything else at all or if this doesn't settle your issue. Thanks and have a fabulous day!