UIBlock collapses in prefab edit mode

[OrionFive]

I don't know what I'm doing wrong. Most of my NovaUI prefabs completely collapse when I edit them. The ones from the samples work fine.

What could be the issue?

Hierarchy

[bai-chi-xing]

[OrionFive]

That's what I've been looking for, thanks, @bai-chi-xing! Never expected to find it there, though.