Legends suddenly have labels

Following template refactor #171, both score and truth plot legends are suddenly labelled when they weren't previously. The score plot label is doubled.

<img src="https://user-images.githubusercontent.com/42820733/137400763-0df4312d-8e44-499f-9d7a-3c3a3dc0a1f0.png" width=40% height=40%>

This only happens in Docker builds, not in Rstudio.