New in 0.12.0, the little disclosure triangle (frontmatter collapse-indicator) is top-aligned with the word METADATA instead of being centered with the text. As of 0.12.1 this is still visible.
0.11.13:
0.12.1:
Spent a few minutes but couldn’t figure out a way to fix this just by tinkering with the CSS found a workaround, see below.