How to keep the (stripe) pattern in the legend when saving a plot (R-ggplot-ggpattern)

Question

I am not able to save the chart as an image (png or other) keeping the **stripe **pattern in the legend. Dot patterns and others work, but not stripes. Could anyone give me some advice? Thanks in advance for your help

My sample problem

library(tidyverse)
library(ggplot2)
library(ggpattern)

data <- data.frame(OBS_VALUE = rnorm(12, 10),
                   COUNTRY = c(rep(c("Flat"), times=6), rep(c("House"), times=6)),
                   SERIES_NAME = rep(c(rep(c("price"), times=3), rep(c("cost"), times=3)), times=2),
                   OBS_DATE = rep(seq(as.Date("2020-01-01"), as.Date("2022-01-01"), "years"), times=4)
)

chart = data %>%
  ggplot( aes(x=OBS_DATE, y=OBS_VALUE)) +
  geom_col_pattern( 
    aes(pattern = SERIES_NAME),
    position = position_dodge(),
    fill            = 'red',
    colour          = 'red', 
    pattern_density = 0.5, 
    pattern_fill    = 'white',
    pattern_colour  = 'white'
  )+
  scale_pattern_manual(values = c(price = "stripe", cost = "circle")) +
  facet_grid(~COUNTRY)
  


ggsave(
  "chart_test.png" ,
  plot = chart,
  scale = 1,
  width = 20,
  height = 10,
  units = "cm",
  dpi=320
)

And the chart appears like this:

Answer 1

It is the combination of scale and width and height which do not fit: Try a scale < 1 or adapt width / height:

ggsave(
  "chart_test.png" ,
  plot = chart,
  scale = 0.9,
  width = 20,
  height = 10,
  units = "cm",
  dpi=320
)