why do i get duplicate null windows in safari 26.1 ?

Safari 26.1 changed how Tab Groups handle background refreshing. If a tab in a group is "stuck," it spawns a null window every time it tries to sync.

• Open Safari.
• Close all Tab Groups: Click the Sidebar icon (top left) and ensure you are viewing just "Start Page" or "Empty Page," not a specific color-coded Tab Group.
• Action: If you have a Tab Group you rarely use, Delete it.
• Test: Quit Safari completely (Cmd + Q) and reopen. If the null windows stop, the corruption was inside that specific group.