Is it a mod compatibility issue?

No

If it's a mod compatibility issue, please provide the link(s) to the incompatible mod(s)

No response

Minecraft version

1.20.4

Describe the issue

1. Create very large portal by doing a command like /portal global create_inward_wrapping 16000 16000 -16000 -16000
2. Teleport to where the portals are supposed to be
3. Notice that there are no portals visible, but if you travel into where they're supposed to be they still work

I traveled along the portal it eventually began to render again at exactly x = 11666

You need to convert the big portal to global portal https://qouteall.fun/immptl/wiki/Portals.html#global-portals Non-global portal's maximum size is 64.

World wrapping portals created by the command that I gave are global portals

I see. Didn't read carefully. Going to check the issue.