Question Rendering (I think) problem with terrain

Hello there,

I have a problem with a game prototype I am working on. I have created terrain by importing a heightmap in the Terrain Toolbox.
The camera has a simple script that allows the player to move it, and when he/she does, for some reason strange white squares or tiles appear/disappear and also change the terrain shape slightly. It is rather hard to explain it, so here is a video of the problem:

At first I thought it has something to do with shadows, so I disabled the Directional Light GO (which is the only light source in the scene)- but it did not solve it.
I hope this is the right place to post this thread, wasn't sure between this or any of the graphics forums.
By the way I am using URP in this project.

I am quite inexperienced when it comes to working with terrain, and will greatly appreciate any attempt to help!
Many thanks in advance and have a wonderful day!