Shiny dashboard and unexpected behavior when rendering datatable (with formatStyle)

Question

I have an R datatable and I am using Shiny to render it into a dashboard.

I want to color a column based on the values from another column. Following the example I see in the DT documentation I can color a column based on the values in each cell:

library(DT)
options(DT.options = list(pageLength = 5))
df = as.data.frame(cbind(matrix(round(rnorm(50), 3), 10), sample(0:1, 10, TRUE)))
# style V6 based on values of V6
datatable(df) %>% formatStyle(
  'V6',
  backgroundColor = styleEqual(c(0, 1), c('gray', 'yellow'))
)

Coloring a single column based on its values works as expected:

Another example from the same documentation claims to allow us to color column V1 based on the values of column V6, and hide V6 from being displayed (this is really what I want to do):

# hide V6
output$table1 <- DT::renderDataTable({

  datatable(df, options = list(
      columnDefs = list(list(targets = 6, visible = FALSE))
  )) %>% formatStyle(
    'V1', 'V6',
    backgroundColor = styleEqual(c(0, 1), c('gray', 'yellow'))
  )
})

However - this does not work when I use renderDataTable in Shiny and I see a column without colors (although it does correctly hide column V6):

I explored further and I can see that the styleEqual is ignoring the fact I asked it to look at V6 and is attempting to apply the styleEqual constraint to V1. If I change this line to backgroundColor = styleInterval(0, c('gray', 'yellow')) then it will color V1 based on the values in V1 (and the V6 argument seems to just be totally ignored).