Area: UIKit / Files / Document Picker (or Safari / WebKit if that category fits better — root UI is Files) Summary On iPhone Air running iOS 26.4 (also reproduced on iPhone Air Simulator with iOS 26.5), presenting the system file picker freezes / becomes unresponsive. The same build and the same iOS major version work correctly on iPhone 17 Pro. This happens for BOTH: WKWebView default file upload panel triggered by Native UIDocumentPickerViewController presented from UIKit So this is not specific to WKWebView’s WKFileUploadPanel alone — it appears to be a Files / File Provider UI issue on iPhone Air. Environments FAILS: Device: iPhone Air (model identifier iPhone18,4) OS: iOS 26.4 (production customer report) Also: iPhone Air Simulator, iOS 26.5 — same freeze WORKS: Device: iPhone 17 Pro (simulator and comparison testing) OS: same iOS 26.x line Also: iOS 18.4 Simulator — file picker works Steps to Reproduce A) Via WKWebView (HTML file input) Open an app that hosts a WKWebView loading a page with Tap the control that triggers file selection System Files UI appears (often on “Recents” / 最近项目) B) Via native UIDocumentPickerViewController Present UIDocumentPickerViewController(forOpeningContentTypes:asCopy: true) for image/pdf types allowsMultipleSelection = true modalPresentationStyle = .fullScreen (also tried default sheet) Actual Results UI opens but hangs / freezes Typical UI state: empty white content area Tabs may still show Recents / Shared / Browse On Browse → “On My iPhone”, content area stays blank and UI is unresponsive Cancel / switching tabs often does not work User cannot select a file; must force-quit the app Expected Results Document picker remains interactive; user can browse and select files (as on iPhone 17 Pro with the same OS). Comparison Environment File picker iPhone Air + iOS 26.4 (device) Freeze iPhone Air Simulator + iOS 26.5 Freeze iPhone 17 Pro + iOS 26.x OK Simulator iOS 18.4 OK Photo library / UIImagePicker OK on Air Photo/camera pickers work on iPhone Air. Only the Files / document picker path fails. Impact Production customers on iPhone Air + iOS 26.4 cannot upload documents (PDF/files) in our hybrid insurance app (WKWebView). Image upload via photo library still works. This blocks claims / document upload flows for Air users. Notes / attempts Not fixed by switching from WKWebView to UIDocumentPickerViewController not fixed by asCopy: true not fixed by fullScreen presentation not fixed by setting / clearing directoryURL App-side workarounds (camera / photo library only) avoid Files UI but do not restore true file picking Please investigate Files / Recents / On My iPhone enumeration hang specific to iPhone Air on iOS 26.4+. Attachments to add Screen recording: freeze on iPhone Air Screen recording: same steps on iPhone 17 Pro (works) Screenshots of frozen Recents / Browse empty state sysdiagnose from iPhone Air if possible (Settings → Privacy & Security → Analytics, or instruct via Feedback Assistant)