e_scatter using data only from column y

[ghost]

This seems strange to me, is it a bug or something to do with a scatter plot I'm not understanding?

e_line plots the data in z as selected:
library(echarts4r); data.frame(x=1:10, y=20:11, z=11:20) |> e_charts(x=x) |> e_line(z)

e_scatter plots the data in z when there's no column y in the data.frame:
data.frame(x=1:10, z=11:20) |> e_charts(x=x) |> e_scatter(z)

but e_scatter only plots the data in y, despite the selection of only z, when y is in the data.frame:
data.frame(x=1:10, y=20:11, z=11:20) |> e_charts(x=x) |> e_scatter(z)

e_scatter_ behaves similarly, e_effect_scatter does not

Thanks.