dotchart() does not draw plot colors

[perNyfelt]

given the following code

png(paste0(getwd(), "/dotchart.png"))
grps <- as.factor(mtcars$cyl)
my_cols <- c("black", "red", "blue")
dotchart(mtcars$mpg, labels = row.names(mtcars),
         groups = grps, gcolor = my_cols,
         color = my_cols[grps],
         cex = 0.6,  pch = 21, pt.cex = 1.5, xlab = "mpg")
dev.off()

The colors are not drawn for the plot characters, only as a faint colorless circle. This code works without problem in GNU R 3.6.3

[perNyfelt]

In Gnu R 3.6.3:

In Renjin 3.5-beta76 6

[perNyfelt]

Upon further investigation, only when pch is set to 19, 20, 21 they are not colored, other values for pch are colored properly.