How to fix significance level in R

Question

I am trying to make a simple LDH graph. Cytotoxicity (%) against normalised data from absorbance values. I have managed to plot the data (triplicates normalised against mean control: Table would be something like this: Normalised data

My code:

# using normalised data 
normalised <- read_xlsx("Data.xlsx")


# convert Norm column to numeric format

normalised$Norm <- as.numeric(normalised$Norm)


# summarise
Norm_sum <- normalised %>%
  group_by(Condition, Experiment) %>%
  summarise(
    mean = mean(Norm),
    median = median(Norm),
    sd = sd(Norm),
    n = length(Norm),
    se = sd / sqrt(n))




# CREATE NEW COLUMN TO COMBINE CONDITION AND EXPERIMENT 
Norm_sum$Condition_2 <- paste(Norm_sum$Experiment, Norm_sum$Condition, sep = "_")


# plot with the new column to add significance level (multiple comparison) comparing WT vs KO in their experimental condition (WT vs KO in Exp A) (WR vs KO in Exp B) etc  #
LDH_fig <- ggplot(Norm_sum, aes(x = Condition_2, y = mean, fill = Condition)) +
  geom_bar(stat = "identity", position = "dodge") +
  geom_errorbar(aes(ymin = mean - se, ymax = mean + se), width = 0.2, position = position_dodge(0.9)) +
  labs(title = "Normalised Data Comparison",
       x = "Experiment",
       y = "Cytotoxicity (%)") +
  theme_minimal() +
  theme(panel.grid.major = element_blank(), panel.grid.minor = element_blank()) +
  geom_signif(comparisons = list(c("Exp A_KO", "Exp A_WT")),
              map_signif_level = TRUE, textsize = 4) +
  geom_signif(comparisons = list(c("Exp B_KO", "Exp B_WT")),
              map_signif_level = TRUE, textsize = 4) +
  geom_signif(comparisons = list(c("Exp C_KO", "Exp C_WT")),
              map_signif_level = TRUE, textsize = 4) +
  geom_signif(comparisons = list(c("Exp D_KO", "Exp D_WT")),
              map_signif_level = TRUE, textsize = 4) +
  geom_signif(comparisons = list(c("Exp E_KO", "Exp E_WT")),
              map_signif_level = TRUE, textsize = 4)`

I don't know why but the significance bars are incorrect showing NS for comparison data, but when run on graphpad I get *** significance. I wonder is there another way that I can do a multiple comparison that shows the correct p-values? Further when I plot condition_2 the x-axis is now too long and I was wondering if that could manually be changed?

Thank you so much for your help!

I am really stuck with this one and I am not sure how to manually annotate significance levels I suppose the x-axis is not a major issue as that can just be fixed via photoshop