I found the issue in Release Candidate 3 and now in the official 1.18 release and 1.18.1 Release candidate2.

The bug causes:

• Some or all chunks to disappear.
• Random chunks to render.
• Chunks far from the player to render before nearby ones.

The bug happens:

• When you load chunks (F3 + A, Loading a world, or respawning) while inside of a block in spectator mode, chunks behind you will not render even when looking at them.

Attached you can find some screenshots of the bug. Also I attached a short video showing how to reproduce the bug.