Approval Notification for Approval has timed out for long with no action.

Summary:

When employee try to approve a transaction that has timed out (raised in Oct last year and it’s still pending for employee to accept, May)

As soon as employee accepted it received an email from I-HUB saying that "the task is now closed and no longer requires my response."

Question:

1.      After how long a transaction gets disappeared from the view of employee under bell icon – Notification?

2.      From where they can go and search that transaction?

3.      If the employee does not take action, does the system automatically approves it? As employee received this email - "the task is now closed and no longer requires my response."