ahh thanks i didn’t see this thread
it does seem to have started around the latest 5.0.3
I’m sure it happens before 5.0.3 because it happened to me 
But thinking about it. I think to have virtual textures + streaming at same time is a bad idea
no mine aren’t virtual textures. And all epic sample projects that use both virtual and streaming textures
At same time? tell me one, because this is the doubt I have
it still shows for me
Try to use shadow maps instead virtual shadows
I managed to solve it by reducing the texture load below my graphics card, and now I have zero corruption.