Problem with xtrans argument since update to visreg 2.8.0

[elenlefoll]

In visreg 2.7, this code produced the desired output, namely the median-centered variable Age_c is plotted on the untransformed Age scale:

visreg(model4_c, 
       xvar = "Age_c", 
       xtrans = function(x) x + median(Dabrowska.data$Age), 
       gg = TRUE) + 
  labs(x = "Age (in years)",
       y = "Predicted Vocab scores") +
  theme_bw()

However, since updating to 2.8, it would appear that the xtrans argument is ignored as the ouput is now:

I saw that the update to version 2.8 includes a fix that concerns the xtrans function (that closed #118). Could this have something to do with it? Thanks!