Error in factor interaction plotted by Visreg. "Error using packet" in outplut plot

Question

I'm using the Visreg package in R with a GLM that includes an interaction effect between two factor variables. The visreg plot shows the first factor level in each panel and the error "Error using packet 1 object 'ind' not found". This is an error on the plot, and not the r console output.

dummyData = data.frame(X = factor(c("x", "y", "z", "x", "y", "z", "x", "y", "z", 
  "x", "y", "z", "x", "y", "z", "x", "y", "z", "x", "y")), 
  Y = c(1683, 2207, 2889, 200, 994, 3960, 2441, 2661, 1262, 3758, 28, 319, 474,
    303, 687, 52, 267, 49, 531, 231),   
  Inter = factor(c("a", "a", "a", "a", "a", "a", "a", "a", "a", "a", "b", "b",
    "b", "b", "b", "b", "b", "b", "b", "b"))) 

testmod <- glm(Y ~ X*Inter, data = dummyData)

visreg::visreg(testmod, "X", by = "Inter", scale = "response")

I expected this code to produce a two panel plot, with 3 lines at the predicted response to each factor level. Resulted in the below plot. Original r version was 4.3.1, but I also tried in 4.2.2 and 4.1.2 (within RStudio). Visreg version 2.7.0.