Sometimes the taskbar on the other monitors gets lost when you have fullscreen (maximized) windows open and the taskbar is set to autohide. This is happening on Beta 12.

You'd bring your mouse cursor down like always and the taskbar won't popup. It's like the maximized windows are hiding it from appearing.

Also, when you click on the Start Menu the taskbar on the main monitor appears.

The Start Menu icon doesn't change when you start changing Windows using something like WindowBlinds. There's some skins out there that change just about everything including the Start Menu button, the Start Menu button doesn't change on the DisplayFusion taskbars even though the one on the main taskbar changed.