With a timid cat, adjustment to the new home will take not days but weeks, or even months. There can be temporary relapses into hiding. Don’t worry about those, they will pass. Even if the cat had begun to trust you, you will notice that there are still things that make it nervous, and there are still limits the cat sets for you. You can touch it, but not pick it up. You can pick it up, but not carry around. As you prove to be a friend, those limits will be gradually removed.
Usually, timid cats are not timid at all with their owners. They will play, wrestle, cuddle, and do other things other cats do. It just takes them a little longer to open up, that’s all.