Spikes are created instead of hills when editting the Lanscape

@SupportiveEntity

$ lspci | grep -i --color ‘vga|3d|2d’ gives this output :

00:02.0 VGA compatible controller: Intel Corporation TigerLake-H GT1 [UHD Graphics] (rev 01)
00:17.0 SATA controller: Intel Corporation Device 43d3 (rev 11)
01:00.0 VGA compatible controller: NVIDIA Corporation GA107M [GeForce RTX 3050 Ti Mobile] (rev a1)

Unreal Engine version is 5.3.0
My OS is Debian 12 (bookworm)

“After editing the landscape this way, can we try saving and closing the project and relaunching? If it looks normal afterwards, we will know our culprit a bit better.”

I tried it yet the result didn’t changed.

Thanks