JackBlack

Here is a link to the video:
https://youtu.be/cEUB0gDNL7Q

Sorry for taking so long to get back to you. I tried to make a video but it was too big, but I have attached some screenshots.
If there is a way for me to attach larger videos or a format to make videos shorter, please let me know.
I used the following commands to fill the nether with blocks:
After first going into the nether to force the portals to generate where the error occurs:
/fill -20 128 -20 20 128 15 minecraft:command_block{Command: "fill ~ 0 ~ ~ 129 ~ glass", auto:1b}

After error to have game force generate portals as all spots are blocked:
/fill -20 128 -20 20 128 20 minecraft:command_block{Command: "fill ~ 0 ~ ~ 129 ~ glass", auto:1b}

No, I didn't misunderstand. Remember, it isn't only what he said, but also what he did.
He posted that the non-scaled radius has been fixed, and closed the issue as works as intended.
That issue was that the radius in the nether is now 16 blocks.
If it was on MC-149705 you would have a point, but it wasn't. It was on MC-197538, which was specifically focusing on the radius in the nether being 16 blocks instead of 128.
This collectively indicates that the range of 16 in the nether is intended.

It is your opinion that the radius in the overworld was too small and the range in the nether correct.
I find it extremely unlikely that they intended for the range in the overworld to be 1024, with the nether being 128, when they have explicitly changed the code to make it 128 in the overworld and 16 in the nether.
It isn't a case of they made a change to the code and it had an unintended consequence of lowering the range in the nether to 16.
Instead, someone put in those numbers. That is clearly intentional.
So this clearly indicates that it is now working as they intend it to.

That means it wasn't wrong because it created unnecessary portals in the overworld, but because it created portals too far away in the nether. It wasn't wrong because it was searching too small an area in the overworld, but because it was searching too large an area in the nether.

The problem now is that it doesn't work the way you want it to, which is not actually a problem for the game. It doesn't actually mean it is not working the way the dev's intended.

That means it isn't a bug that the range is so small, it is you wanting the range to be larger, which is a feature request.

And no, it previously being larger doesn't mean it is a bug either. Or do you think the texture changes are a bug, and the introduction of new mobs are bugs? Because in both cases the game doesn't work the same. An intended change is not a bug.

Yes, that issue is good as it has the code as well, and again, it is focusing on the 16 block range in the nether (and thus this issue is a duplicate of it). As such, the status and comment by Grum indicate it is intended.
It doesn't mean it shows both places where the code is wrong. Again, it is your opinion that it is wrong.

As for turning 3 blocks into 1024, what I mean is as follows:
Nether travel is meant to be 1 to 8, where walking 1 block in the nether corresponds to 8 in the overworld, so 128 in the nether is 1024 in the overworld.

e.g. you go into a portal, enter the nether, walk 128 blocks, and then go through another portal, enter the overworld 1024 blocks away from the original portal.

What you are trying to do is go through to the never, walk 3 blocks (or possibly less), and leave the nether, appearing 1024 blocks away.
i.e. you are trying to turn 3 blocks into 1024, instead of the 24 they should be changed into.

I also gave options other than walking, like flying with an elytra.
Yes, it takes more effort, but is far less exploitive (and that may be another reason other than better performance that they reduced the range).
Personally, I would prefer that to just switching back and forth between portals, especially as it allows other portals nearby.

@Raydon8472 
The wiki is not the sole source of truth, and it can be wrong and has been wrong at times.
Grum, a Minecraft developer, has indicated it works as intended. So it is quite possible they intended to reduce the range, possibly due to having such a large search area in the overworld (and the reduction of the range in the overworld was apparently done in 1.14, when the portals were optimised).

So it is not clear that it does not work as intended. It apparently does work as intended, but clearly not as YOU want. But you wanting something is not the same as the developers of the game intending it.
Even if it changes from prior behaviour, it is still not the same as the devs not intending it.

Even if it is wrong, that doesn't change the fact that both this issue and the one this is marked as a duplicate of are both dealing with the range in the nether.
Your issue is focusing on entering portal A in the overworld not linking to portal B in the nether, because the range in the nether is 16 blocks not 128.
MC-197538, which this issue has been marked as a duplicate of, is that the range in the nether has been reduced to 16 blocks. As such, it is a duplicate.
They are quite literally the same issue. Both are focusing on the range in the nether being reduced to 16.

MC-149705 is the one dealing with the range in the overworld not being 1024 blocks, or more specifically that the range in the nether and overworld were both 128 blocks and thus it did not scale, and thus you could go to the nether and go back and have a new portal generate. But that is not the issue that this issue has been marked as a duplicate of.

Have you actually looked at MC-197538, or did you just assume this was labelled as a duplicate of MC-149705?

As for long range travel in the nether, like I said, don't try turning 3 blocks into 1024.
It is meant to be 1 to 8.
If you need to travel 1024 blocks, then setup a path in the nether that is 128 blocks long, with a portal on either end.
The advantage of this method is you can have other portals nearby without it breaking.
For longer routes, it can make far more sense to make a long path in the nether than repeatedly using portals, given it takes roughly 4 seconds to travel through the portal, thus to travel 1024 blocks in the old system would take 8 seconds (plus a bit for loading and walking between).
If you use a boat on normal/packed ice, those 8 seconds allow you to cover 320 m, which equates to 2560 in the overworld.
Blue ice almost doubles that.

Using an elytra gives you 2144 m.
If you really need to go all out, use an ender-pearl cannon.

@Radon8472, it is the same issue.
You enter A, it then searches for an existing portal.
The radius you expected was 128 blocks to make it reach portal B.
But the radius it actually checks is 16 blocks.
Portal B is not within 16 blocks, so it doesn't link there, and creates the portal at X.

Your issue is that the search radius is not the 128 blocks you expect. The other issue is that it is only 16.
They are the same issue and thus the other ticket being resolved as works as intended means this ticket is resolved as works as intended.

They have intended to make the range in the nether 16 blocks. Your portal is not within 16 blocks and thus it is intended that it doesn't link.

Long range travel in the nether still works, not just trying to turn 3 blocks into 2048.

me too

The symbol for kilo, the SI prefix meaning 1000, is k. The symbol for kilogram, the combination of the SI prefix kilo with the unit of mass gram, is kg, kilometre is km, kilobyte is kB, and so on.
But they are all used as prefixes, and while the K is still indicating "1000", 4K doesn't have 4000 columns of pixels, but roughly 4000, and it is a suffix.