Hi, I’m experiencing a persistent issue with the iOS on-screen keyboard in mobile Safari. My website (built with PHP, but the issue is clearly on the frontend) has a fixed header (position: fixed; top: 0). However, when a user focuses on an input field and the keyboard opens, the entire viewport shifts upward. No matter what I try, the keyboard seems to push everything up: The header does not stay fixed at the top of the screen In some cases, it briefly stays, then animates/jumps as if trying to reposition itself It feels like the whole layout is being moved rather than just the visible area adjusting I’ve already tried: Removing transforms on the header Forcing position: fixed with top: 0 Avoiding 100vh Testing without custom JavaScript related to viewport handling But the behavior remains the same: opening the keyboard causes the entire layout to shift. Is this expected behavior due to how iOS handles the visual viewport? Is there a reliable way to keep a fixed header truly fixed when the keyboard appears? Any insight or recommended approach would be greatly appreciated. Thanks!

We are investigating a web application performance issue observed in iOS Safari/WKWebView after a recent iOS/Safari update. In the network waterfall, the main backend/document request completes within an acceptable time, but JavaScript resources appear to load late and in a more sequential pattern. We also noticed duplicate requests for some static JavaScript assets, which further delays full page rendering. The issue is more visible in iOS Safari/WKWebView compared with other browsers/environments.