love.plot var.names 图片显示变量名显示"X_2"

问题遇到的现象和发生背景

love.plot var.names 图片显示变量名显示"X_2"

问题相关代码，请勿粘贴截图

psm<- matchit(Group ~Age+Gender+Comorbidity)
new.names <- c(Age = "Age",
Gender="Gender",
Comorbidity="Comorbidity",
)

love.plot(psm,drop.distance = TRUE, binary = "std",abs = TRUE,thresholds = c(m = .1),
shapes = c("triangle", "circle"),
colors = c("blue", "red"),
var.names=new.names,grid = FALSE, wrap = 20,
sample.names = c("Before PSM", "After PSM"),
position = "top")

运行结果及报错内容