I've also attached screenshots, once in 1.17.1 and once in 1.18.
In doing so, something odd happened: if I open the world once in 1.17.1, fly over there, log out and then open it in 1.18, it works fine. But if I open the copy directly in 1.18, it is broken.
Edit: It seems that opening the world once locally in 1.17.1 before opening it in 1.18 does fix it, regardless of flying to the location (at my log-in location those chunks are loaded, though).
Edit: Yeah, I now was able to fix the world on my actual server by opening it once locally in 1.17.1, then 1.18 and then uploading it back to the server. I'll leave this open anyway since the example can reproduce the issue.
I've also attached screenshots, once in 1.17.1 and once in 1.18.
In doing so, something odd happened: if I open the world once in 1.17.1, fly over there, log out and then open it in 1.18, it works fine. But if I open the copy directly in 1.18, it is broken.
Edit: It seems that opening the world once locally in 1.17.1 before opening it in 1.18 does fix it, regardless of flying to the location (at my log-in location those chunks are loaded, though).
Edit: Yeah, I now was able to fix the world on my actual server by opening it once locally in 1.17.1, then 1.18 and then uploading it back to the server. I'll leave this open anyway since the example can reproduce the issue.