My landscape hills look like squares, glitchy out of nowhere?

A lot of my maps in UE 5.4 suddenly look deformed when it comes to hills or smaller slopes. Basically huge square blocks like Minecraft. I don’t know if it’s a texture thing, shadows, or whatever. The closer I get, the worse it is, whereas from far it looks okay.

This is when I try to sculpt it (minimum strength) to see if it helps (it doesn’t haha).

These are all demo maps so I didn’t edit them or create them on my own, and they were working normally for months. Never updated anything, but now when I open them some foliage doesn’t load properly (LOD, materials, texture; what’s the problem?) and the hills just look horrible. Like 80% of maps looks fine, but 20% just decides to go super weird.

Things that didn’t help:

  • r.streaming.poolsize increasing to max
  • Removing & Adding from Epic Library
  • Starting a new project and adding from library

Is there some way to reset, rebuild textures, cache, whatever? Thanks

My PC is fine (RTX 2080, 32GB ram etc), quality LOW or EPIC doesn’t change it. I’m not sure if it’s some texture problems that go corrupt, but it still makes no sense that it would act the same in a NEW project.

Landscape problem - Imgur: The magic of the Internet
When trying to sculpt - Imgur: The magic of the Internet