Exactly: Who wouldn’t doubt to see a dead man alive? It was the “eating” that made the doubts vanish.
This took place way after he allegedly ate and after their eyes were allegedly opened, and after they allegedly received the HolySpirit. This took place the last day Jesus was on earth according to the Bible, 40 days after his curcifixtion, on the Pentecost. Your time frame is a little off.