When using different Nether portals in the over world they all go to the same on in the nether. I had one portal at my home and another in a village about 800 blocks away and they go to the same original portal in the nether. Now just recently I found a ruined portal about 1000 blocks from home and it also took me to my original portal.
MC-182288
Every Overworld Portal Leads to the same Nether Portal
Resolved
Invalid
0
This is how it's supposed to work. Check out https://minecraft.gamepedia.com/Nether_portal#Portal_linkage_between_Overworld_and_Nether for details. In a nutshell, every block you travel in the Nether, you travel 8 blocks in the overworld and vice-versa, and nearby portals link together.