Description of the bug

After updating Microsoft Edge to version 143, the Vaadin application no longer starts reliably. A blank screen is frequently displayed, especially when launching the application for the first time. The issue appears to be related to a timing problem involving the service worker. In the browser’s Developer Tools, the service worker is shown as running, even though the application remains blank.

Expected behavior

No blank screen.

Minimal reproducible example

See Business Starter App.

Versions

• Vaadin / Flow version: 24.9.6
• Java version: 21
• Browser: Microsoft Edge (143)