I hit a strange bug on all iPad models that I tested (various simulator versions, hardware iPad Pro M4 11"), reproducible on iOS 18.4 and 17.5 but not on 16.4 or 15.5. It looks like a regression introduced with the viewport changes in 17.0, then. Setup: a simple webpage, with an element that triggers full-screen. Enter full-screen, exit full-screen, now page can be pulled down beyond the top of the page, and a 24px persistent gap remains. Reloading the page doesn't help, force-closing Safari and reopening it fixes the issue. Example: http://k1024.org/fullscreen-bug.html This is reproducible on multiple iPad models, simulator and hardware, in landscape and portrait mode, with or without a tab bar. The very consistent 24px makes me think it's related to some Safari UI element, and the transition into and out of fullscreen misses re-adding (or re-subtracting) it from the viewport size. Let me know if you need more information.