legend in RMarkdown

[koolmees]

I am trying to add billboarder charts in my .Rmd but if it's not located on the landing page the legend isn't loaded correctly. This is a simply example of the problem:

---
title: "Untitled"
output: 
  flexdashboard::flex_dashboard:
    orientation: columns
    vertical_layout: fill
---

```{r setup, include=FALSE}
library(flexdashboard)
library(billboarder)
library(data.table)
```

Column {.tabset}
-----------------------------------------------------------------------

### Dummy tab


### Chart A

```{r}
billboarder() %>%
  bb_linechart(melt(data.table(rock, keep.rownames = TRUE)[, area := as.numeric(area)], id.vars = "rn", measure.vars = c("area", "peri")), bbaes(rn, value, variable))
```