Steps to reproduce

1. In the overworld, create a portal some distance above the ground.
2. Save & quit, then reload the world.
3. Break the nether portal
4. About 10 seconds later, force close the game or do something to crash the game (e.g. Alt-F4)
5. Reload Minecraft and open the world.
6. Verify that the portal you broke in step (3) is broken.
7. Create a nether portal on the ground, under the frame of the other portal, and go through it.
8. In the nether, fly straight up from the generated portal until your Y-coordinate is higher than the portal you made in step (1), and make a portal there.
9. Go through that portal.

Expected result

You appear in the overworld in the portal that you made on the ground.

Actual result

You appear in the overworld in the portal frame up in the sky (or at its position, if you broke the entire frame). The attached world MCPE-73179 Ghost portal.mcworld contains a ghost portal that was made following the steps above.

I had a Nether portal linking right next to a Blaze farm. After setting everything up (this farm in particular used a lot of pressure plates and Pistons to move the Blazes around) it worked well for a while. A separate player enter this nether portal, and the entier chunk containing the nether portal and Blaze spawner was gone from [-80, 64, 15] to [-65, ??, 0] (unsure how high up was deleted, but the nether roof is still there). Just a cube of air blocks, with a netherrack floor on y64 and the bottom half of my blaze farm sans blaze spawner/the top half. Five minutes earlier the farm and portal were still there as I had recently passed by that area.

Now I know this chuck deletion bug is a known issue which isn't why I'm entering this report. For whatever reason the nether side portal is still "active" despite not actually being there. When I enter the nether from the overworld, I spawn a few blocks in the air at the old portals coordinates and fall down. I can't enter this ghost portal from the nether side though, it's just an exit point into the nether. While trying to build a netherhub nearer to the ceiling I attempted to relink the overwold portal to a new one on the nether side, but no matter what I do I enter in the same spot as the ghost portal in the Nether. A couple solutions I have tried:

1)Place down a new nether side portal closer to the ghost portal and matching the overworld side coordinates (divided by 8). I can exit the nether using these just fine, but they never work for entering the nether. The ghost portal has priority for linking it seems.

2)Remove and place down a new portal on the overworld side. Result: only portals sufficiently far enough away from my base works. Anything around about 70 blocks seem to want to link up to the ghost portal, regardless of additional normal portals built in the nether.

3)Place down solid block covering the entier area where the Ghost portal is, and place down a new nether side portal nearby. Result: I enter into the ghost portal location, which is now solid blocks, and begin to suffocate.

4)Place down a nether portal in the exact location as the ghost portal. Enter and exit. Then break both the portals down + build a new nether portal nearby. Result: I still end up in the same coordinates as the ghost portal.