If your App Store listing says your app supports iPhone and iPad but the iPad version looks like a blown-up phone app — or crashes entirely — you're going to hit 2.5.4. Apple reviewers test on the devices your listing claims to support. Here's how to fix it.
What Apple said
“Your app does not function as expected on iPad. When we launch the app on an iPad, the layout appears broken and the interface does not adapt to the larger screen. Apps must work correctly on all compatible devices listed in the App Store.”
Apple tests your app on every device family your listing claims compatibility with. If you checked 'iPhone and iPad' in App Store Connect but only designed for iPhone, the stretched or misaligned iPad layout will get you rejected under 2.5.4. You either need to fix the iPad experience or remove iPad from your supported devices.
While you're at it — Apple also requires these pages for every app.
Fix this rejection, then make sure you're covered on the compliance side too. Apple requires every app to link to a hosted Privacy Policy, Terms of Service, Support page, and Data Deletion page. No link means another rejection — just for a different reason.