While exploring the map I found ruins. But when I gon in them, the world started loading for me as if I was entering a dungeon. After that I appeared as at the beginning of the game near the balloon, the old chester disappeared, a new one appeared without my old things. All the items that I had with me were preserved, the day counter remained the same. It's the same world, only the map is not explored, like a restarted world.

Is this how it should be or is it a bug?