Sometimes Virtual Textures don't render on World Composition landscapes, possible bug?

Hi, I’m using Virtual Runtime Textures in World Composition for each landscape. And I’ve included some screenshots of the issue I’m seeing. Both in editor and playtime, some landscapes render as black, while some render correctly, with some “nudges” or some updates some of the black landscapes get rendered correctly again, however other previously correctly rendered landscapes become black, in turn. I’m wondering if there is something that I’m doing wrong, or if it’s bug?

Screenshots:

Same issue here. Any hints ?