R 如何修复STAT_POLY_EQ中的坡度计算

我使用stat_poleq在图形上显示了计算出的线性方程，但显示的结果与实际结果相差很大.实际坡度不能大于0.5. 有人能帮我改正这个错误吗？ ​

以下是我的数据:

df<-structure(list(Variety = c("Sultana - MG 000", "ES Pallador - MG I", 
"Isidor - MG I", "Santana - MG I/II", "Blancas - MG II", "Ecudor - MG II"
), FTSWt2017 = c(0.54, 0.47, 0.41, 0.18, 0.25, 0.18), FTSWt2021 = c(0.32, 
0.27, 0.35, 0.29, 0.22, 0.32)), class = c("tbl_df", "tbl", "data.frame"
), row.names = c(NA, -6L))

下面是我的代码:

library(ggplot2)
library(ggpmisc)
library(ggrepel)
library(stringr)
library(stats)
ggplot(df, aes(x = FTSWt2017, y = FTSWt2021)) +
  geom_point(aes(color = Variety)) +
  geom_smooth(method = "lm", formula = 'y ~ x', se=FALSE,color="black") +
  geom_abline(intercept = 0, slope = 1, color="gray", 
              linetype="dashed", size=0.5)+
  (
    aes(label = paste(
      gsub(
        '\\.',
        "*paste('.')*",
        str_replace_all(after_stat(eq.label), "\\.([0-9])[0-9]", "\\.\\1")
      ),
      gsub('\\.', ".", after_stat(rr.label)),
      sep = "*plain(\";\")~~"
    )))

以下是输出图:

enter image description here个