Decreasing Terrain LOD helps !

Tested with this scenery only, in my community folder.

But why such problem with this scenery, specifically ?

Exactly the same for me. With an Intel i9 10850 and a Nvidia 3090.

I can confirm, this is not a problem with my computer, msfs2020 neither. Other sceneries work fine.

Is there a conflict with another scenery ?

Boston scenery bought on Orbx Central E-shop.

David