Nether Portal is kinda broken

When you use the Nether Portal (NP for short), you'll get there as normally. But if you exit the Nether, the NP take you to another place instead of the Original NP that you used to enter the Nether. Before you ask: "Is the NP that you entered broken?", I'll answer already: No! It isn't. I came back to my home to overlook, and it wasn't broken.