Device and OS fragmentation, Appium, real device versus emulator trade-offs, and mobile-specific defects.
3 questions in QA & Testing.
Treat each launch state as its own test case, because each delivers the link through a different code path. Cold start runs splash, auth and initialisation that can drop the link, and on iOS delivers it in the scene's connection options, not the continue callback. Test cold, warm, restored and logged-out.
Pick devices from your own analytics rather than from a market-share article, spread the choice across OS version, screen size, memory class and manufacturer skin, and keep real hardware for anything involving the camera, sensors, radios, battery or vendor-modified behaviour.
Mobile adds four things a browser mostly hides: a device and OS matrix you cannot enumerate, a network that degrades and disappears mid-request, an operating system that interrupts and revokes permissions at will, and hardware behaviour that emulators cannot reproduce.