We have a server running in linux that we created in 1.15.
When 1.16 arrived, we renamed the nether world file by adding a .backup, so that it would generate a new nether for us, which it did... However, when we go through our portals, it does not create new portals or link to portals we build there. Instead it uses the coordinates of the portals before the reset and teleports us to the middle of nowhere, where those portals used to be, with no way to return...
We do have a few datapacks, but it is unlikely that they are interfering with this...
Video of the issue:
YouTube Video
All portals shown in the nether in the video above are player buildt.
Comments 2
The link you provided describes a behaviour completely opposite of what is happening...
1) Why is the game "remembering" coordinates from the old nether, and constantly forcing teleportation there when it's only supposed to hold them for about 15 seconds, as the wiki states?
2) Why is no new portal created when there's no portal there?
https://minecraft.gamepedia.com/Nether_portal#Portal_linkage_between_Overworld_and_Nether
This is intentional, manually resetting the nether is not officially supported and can cause issues like this.