I am on an Android Moto Z^2 Play phone.
When building nether portals, the first pair work as expected. But when you build a second nether portal in the overworld, it will link to the original portal in the nether from a much farther distance. I have personally tested it at over 500 blocks (the distance between the two overworld portals), and have heard rumors of well over a thousand blocks. You can still link up portals properly, just makes it much more difficult as you have to travel to the desired location on foot in the nether.
How to recreate this bug:
Build a standard nether portal (4×5 obsidian frame, although I'm sure you know that XD)
Go through the portal and stay in the nether waiting for the player cool down for going through portals. (Not essential but I recommend placing a non-nether block as a marker for that portal ie. Cobblestone or clay)
Go back through the portal you just came out of, you should come out of your original portal.
Go roughly 500 blocks away from your original overworld portal (as I said I have heard it rumored much farther so you don't have to be overly finicky with it)
You should see that you appear in you original portal in the nether.
Comments 2
This is most likely working as intended. 500 blocks in the overworld corresponds to only 62 blocks in the nether, which is well within the 128 block range that gets searched for a nether portal to transport you to. Although it's not a simple number (you have to actually do a calculation which involves finding the boundaries of chunks),it's likely that two overworld portals within 1024 blocks will link to the same portal in the nether. To get two overworld portals closer than that to link to separate portals in the nether, you have to build at least one of the pairs' nether side first, at least 17 blocks away from any existing portal.
From the wiki: "Overworld portals that are within 1024 distance of each other on both X and Z axis are almost always going to link to the same Nether realm portal on initial construction because 1024 translates to a distance of 128 in the Nether Realm, and the game checks for existing portals within 128 "radius" around the destination (the 257×257×128 box)." You may want to view the wiki article Tutorials/Nether portals for help on how to accomplish what you're trying to do.
Non refundable was supposed to say non-nether, autocorrect 🙂