Exporting editable ggplot2 graphs to PowerPoint (properly)

Hi All,
I want to export ggplot2 graph to PowerPoint, but when I do it the regression equation
is going to be distorted. Why is that ? What should I do better ?
I want my graph to be editable in Powerpoint , when I export as bitmap obviously everything is OK, but is not editable.

library(tidyverse)
library(ggpmisc)
#> 
#> Attaching package: 'ggpmisc'
#> The following object is masked from 'package:ggplot2':
#> 
#>     annotate
library(rvg)
library(officer)

fit <- lm(disp ~ mpg, data = mtcars)

ggplotRegression2 <- function(fit) {
  
  require(ggplot2)

  ggplot(fit$model, aes_string(x = names(fit$model)[2], y = names(fit$model)[1])) +
    geom_point() +
    stat_smooth(method = "lm", col = "red") +
    labs(title = paste(
      "Adj R2 = ", signif(summary(fit)$adj.r.squared, 5),
      "Intercept =", signif(fit$coef[[1]], 5),
      " Slope =", signif(fit$coef[[2]], 5),
      " P =", signif(summary(fit)$coef[2, 4], 5))) 

}


p <- ggplotRegression2(fit)

my.formula <- y ~ x

y <- mtcars$disp

x <- mtcars$mpg

p + labs(title = paste(
  "Adj R2 = ", signif(summary(fit)$adj.r.squared, 5),
  "Intercept =", signif(fit$coef[[1]], 5),
  " Slope =", signif(fit$coef[[2]], 5),
  " P =", signif(summary(fit)$coef[2, 4], 5)
), subtitle = "My subtitle", caption = "My caption") +
  geom_smooth(method = "lm", se = TRUE, color = "red", formula = my.formula) +
  stat_poly_eq(
    formula = my.formula,
    eq.with.lhs = "italic(hat(y))~`=`~",
    aes(label = paste(..eq.label.., ..rr.label.., sep = "*plain(\",\")~")), parse = TRUE, label.x = "right", geom = "label_npc", alpha = 0.33)
#> `geom_smooth()` using formula 'y ~ x'


p2 <- p + labs(title = paste(
  "Adj R2 = ", signif(summary(fit)$adj.r.squared, 5),
  "Intercept =", signif(fit$coef[[1]], 5),
  " Slope =", signif(fit$coef[[2]], 5),
  " P =", signif(summary(fit)$coef[2, 4], 5)
), subtitle = "My subtitle", caption = "My caption") +
  geom_smooth(method = "lm", se = TRUE, color = "red", formula = my.formula) +
  stat_poly_eq(
    formula = my.formula,
    eq.with.lhs = "italic(hat(y))~`=`~",
    aes(label = paste(..eq.label.., ..rr.label.., sep = "*plain(\",\")~")), parse = TRUE, label.x = "right", geom = "label_npc", alpha = 0.33)

#as vector graphic
t <- "example.pptx"

fig_vg <- dml(ggobj = p2)

read_pptx() %>% 
  add_slide(layout = "Title Only", master = "Office Theme") %>% 
  ph_with(fig_vg, location = ph_location(left = .5, top = 1.3, height = 5, width = 5)) %>% 
  print(t)
#> `geom_smooth()` using formula 'y ~ x'

#as bitmap
t <- "example.pptx"

fig_vg2 <- p2

read_pptx() %>% 
  add_slide(layout = "Title Only", master = "Office Theme") %>% 
  ph_with(fig_vg2, location = ph_location(left = .5, top = 1.3, height = 5, width = 5)) %>% 
  print(t)
#> `geom_smooth()` using formula 'y ~ x'
Created on 2020-11-15 by the reprex package (v0.3.0)

obraz

Any help is much appreciated,

regards,