Values from dataframe are switched/changed on stacked bar plot ggplot2-CodePudding

I have a df that I intend to visualise as a stacked percentage bar plot, with the stacks ordered in descending order. The df contains values in proportion and has been transformed into long format. Below is a reprex with some dummy data that is based on the real data I'm using.

df<- data.frame(ID=c("A","B","C","D","E"),
                a1=c((0.452),(0.558),(0.554),(0.484),(0.661)),
                a2=c((0.326),(0.373),(0.465),(0.434),(0.499)),
                a3=c((0.450),(0.481),(0.613),(0.473),(0.504)),
                a4=c((0.561),(0.681),(0.633),(0.504),(0.723)))

dflong<-df%>%
  pivot_longer(!ID, names_to="aa", values_to="prop")

dflong$ID<-as.factor(dflong$ID)

# A tibble: 15 × 3
   ID    aa     prop
   <fct> <chr> <dbl>
 1 A     a1    0.452
 2 A     a2    0.326
 3 A     a3    0.45 
 4 A     a4    0.561
 5 B     a1    0.558
 6 B     a2    0.373
 7 B     a3    0.481
 8 B     a4    0.681
 9 C     a1    0.554
10 C     a2    0.465
11 C     a3    0.613
12 C     a4    0.633
13 D     a1    0.484
14 D     a2    0.434
15 D     a3    0.473

dflong %>%
  ggplot(aes(x=ID,y=prop, fill=reorder(aa,-prop)))  
  geom_col(position ="fill", data=dflong%>%filter(ID=="A"))  
  geom_col(position ="fill", data=dflong%>%filter(ID=="B"))  
  geom_col(position ="fill", data=dflong%>%filter(ID=="C"))  
  geom_col(position ="fill", data=dflong%>%filter(ID=="D"))  
  geom_col(position ="fill", data=dflong%>%filter(ID=="E"))  
  geom_text(aes(label=scales::percent(prop)),
            position=position_fill(vjust=.5), size=3, colour="black")  
  scale_y_continuous(labels = NULL, breaks = NULL) 
  scale_fill_brewer(palette="GnBu",
                    name="") 
  coord_flip() 
  theme_minimal() 
  theme(legend.position = "bottom",
        legend.direction = "horizontal")  
  labs(caption="",
       x="",
       y="")

My problem is that the resulting plot will always switch between the 2 values within the variable "C", that is the stacked bar chart will exchange the values of C-a1 and C-a3. The image of the plot will demonstrate the issue clearly.