Question: VectorScope display pattern?

[Angelo]

When I view footage from the timeline with Vector Scope the chroma is all filled in nicely. As soon as I color correct and increase chroma the Vector Scope shows the chroma cross-hatched, why? Are some colors missing, why is there black thin lines (cross-hatch) in the chroma?

With ProDAD's Vitascene increasing chroma, Vector Scope shows-up all nicely filled in, NO cross hatching.

Thanks...Angelo