I recently built a second Nether portal (on my cell phone). A second one was also generated in the Nether for this purpose. Everything worked. Only when my friend (PS4) goes into the second portal in the Nether does he spawn somewhere that doesn't even have a portal. If he goes into the same portal in the upper world, he will spawn again somewhere in the upper world where again there's nothing. What's going on there?!
Bug! Anything else would be weird! Maybe just restart the server…
if that doesn't work, I can't help you at first.
This is a normal world, not a server
The portals are too far away. You have to link them with coordinates. Just search for "Link Minecraft Netherportal" on YouTube