The app I work on uses WKWebView to render customer data. In iPadOS 26, we observe that there is a delay when resizing the window (and thus the web view) before the content is re-rendered. The same behavior is visible in Safari.
For demonstration purposes, consider this test page: https://phet-dev.colorado.edu/html/build-an-atom/0.0.0-3/simple-text-only-test-page.html
Initially, the window is small:
Then when the window is expanded, the content scales up temporarily:
It eventually re-renders to the correct size, but then if you make the window small again, you get (temporarily):
Is there anyway around this behavior? We would love to have the content reflow interactively.