Expected behavior
When max opened Toasts is set to 1 further Toasts are queued and opened after the previous toasts Timeout (if not cleared manually). At least, the Documentation indicates so: "Max alerts opened, alerts will be queued (0 means unlimited)"

Actual behavior
With the following configuration further Toasts are lost if another toast is still active:

ToastModule.forRoot({ maxOpened: 1 }),

if we add "autoDismiss: true" the currently active toast will disappear and the new one won't show up.

I've looked a bit into _buildNotification and I guess there is no real queueing mechanism if the max number of toasts is reached (keepInactive / early return)?
But at least the 2nd behavior could be fixed if "keepInactive" would be set to false when autoDismiss is active, so the old toast is cleared and the new one shown.

Would be nice to know if this kind of queueing should work or if you're planning to support such a behavior or if we have to build our own queueing system for toasts.