On iOS 26.5, combining the .inlineLarge navigation bar mode with a custom ToolbarItem(placement: .largeTitle) breaks the collapsed bar: after any scroll collapse, the compact bar renders with no title, no bar material or scroll edge treatment, and content draws through the status bar. It recovers on re-expansion.
Details from my minimal repro (filed as FB24528594, single-file project attached to the report):
- The .title item is not required to trigger it. .inlineLarge plus only a custom ToolbarItem(placement: .largeTitle) reproduces it on every collapse.
- A .largeSubtitle item alone does not trigger it. Adding one alongside the .largeTitle item breaks the same way, with the subtitle content vanishing too.
- Reproduces 100% on the iOS 26.5 simulator (Xcode 26.6), light and dark.
- Workarounds tried without success: setting navigationItem.titleView does not hold, because SwiftUI re-renders the compact title after toolbar churn.
Two questions for the engineering team: is this a known bug, and is there any supported way to keep a custom large-title toolbar arrangement while preserving the compact bar's title and material through collapse? I have a design that places an avatar in the large-title row and this is currently the blocker. Happy to provide anything beyond what's in FB24528594.