Webpages hijack the alt+number for changing tabs
When you want to switch tabs using the alt shortcut in Gnome Web, certain web pages like Facebook hijack the control. You can try it yourself by going to Facebook and try to switch tab using the keyboard shortcuts. It would be good if that could be disabled and have web page keybindings only enabled for web apps. Alternatively changing the keybinding to switch tab to ctrl+number.
This is running Gnome Web 3.30.2