Help needed. I've saved a site as desktop "app" (PWA) in a Chromium-based browser on macOS. As soon as I leave the main/entry URL, a bar appears between window title bar and webview. Ex: Fastmail inbox saved as desktop shortcut ("Chrome app"), when I enter another folder, bar pops up.
1. What's the name of this UI element?
2. Is there a way to hide it for good by way of settings, flags, incantation to an Elder Goddess or config file?
Any help is appreciated. TIA!














