As I see many others are experiencing. I was unable to log in during the 12/09/24 , 12/10/24 , and 12/11/24 and the gifts are simply grayed out and unclaimable
As mentioned above, gifts are available on the day, and for a further two days grace period after this (3 days total). Unfortunately, if a gift has not been claimed during this time then it will have been missed sorry for any disappointment.