By default the Alt+Tab functionality groups windows of the same application together. That means when we have multiple browser windows open it is very cumbersome to use Alt+Tab to switch between them.
You might just want to switch between windows instead of between applications.
By default the Alt+Tab shortcut is by linked to the Switch Applications function of Gnome. Though this is easily changed. Go to the Gnome Settings application and go to the Keyboard section.
At the bottom you will find the View and Customize Shortcuts section. Here you can Alt+Tab binding. Search for switch window and you will find the Switch Windows functionality.
Now just change the shortcut to Alt+Tab.
Now using Alt+Tab does not switch between (grouped) applications anymore, but between windows instead.