The Cookie associated with the "Remember This Choice" option for IdPs only lasts for the current session

[norealroots]

As per the title, the cookie saved in browser when a user selects the "Remember this choice on this computer" option after selecting an IdP will only persist for the duration of the current session. This means that more often than not most users will not see any benefit to this option.

The option presented to a user

Cookies associated with the page after returning to it - as you can see both have a max-age of Session

Ideally the cookie saved should persist for longer than one session, so that a user may benefit from the option of requesting their choice to be remembered.