The release notes for this version state:

ROU-12349 – Removed the JavaScript that forced a static pixel value into the --viewport-height CSS variable … Layout CSS now uses layered 100vh/100dvh fallbacks instead, so it tracks the real visible viewport.

The JS removal is in the release. I could not find the CSS changes in the OutSystems UI CSS. Searching the shipped OutSystemsUI stylesheet for dvh returns zero matches, and --viewport-height is still referenced in two rules with no working fallback:

1. .ios .layout-native.ios-bounce:not(.hide-header-on-scroll) .main { max-height: var(--viewport-height, 100vh); }
   With the variable unset this falls back to 100vh, which in a standalone iOS PWA with an opaque status bar resolves to full screen height, not the webview height.
2. .phone .osui-dropdown-serverside__balloon--has-not-search .osui-dropdown-serverside__balloon-container { max-height: calc(var(--viewport-height) - 5vh - var(--header-size)); }
   No fallback at all. The declaration is invalid and dropped, so the balloon has no max-height.

Environment: OutSystems 11 Reactive, distributed as a PWA (no MABS / Cordova), OutSystemsUI 2.30.0. Reproduced on iPhone 17 Pro, iPhone 15, and iPad, all iOS 17, standalone (home-screen) mode. Not reproducible in Chrome iOS emulation because it reports env() insets as zero.

Symptom: Bottom bar (.content-bottom) sits 62px below the visible screen edge on the iPhone 17 Pro and does not scroll into view. Server-side dropdown balloons open with no height limit. Prior OutSystemsUI version on the same devices is unaffected.

Diagnostic readout from device (iPhone 17 Pro):

innerHeight 812html.clientHeight 812visualViewport 812docScrollHeight 874--viewport-height ""--os-safe-area-top max(0px, 0px)--os-safe-area-bottom max(34px, 0px)layout: layout layout-side layout-native ios-bouncemain 874 / 874 | grid | max-h 874pxcontent 728 | overflow-y autofooter 90 / 874 | relative

main is sized to 874 (100vh) while the viewport is 812. The 62px difference is the status bar.

Workaround applied in app theme (pending a fix):

css.ios .layout-native.ios-bounce:not(.hide-header-on-scroll) .main {  max-height: 100vh;  max-height: 100dvh;}.phone .osui-dropdown-serverside__balloon--has-not-search .osui-dropdown-serverside__balloon-container {  max-height: calc(100vh - 5vh - var(--header-size));  max-height: calc(100dvh - 5vh - var(--header-size));}

This resolves the iPhone. On iPad, env(safe-area-inset-top) reports a non-zero value even when the webview is positioned below the status bar, so .ios .layout .header { padding-top: var(--os-safe-area-top) } adds padding for a status bar the header isn't under. That may be a separate WebKit issue but is worth noting since it surfaces alongside this one.

I feel like I am missing something, I've spent hours trying to diagnose this.