robust GWR produces same results as basic GWR

Hello, I am unable to reproduce the results for robust GWR models provided in in the package documentation. For example, executing the code examples for the `gwr.robust()` function (e.g. https://rdrr.io/cran/GWmodel/man/gwr.robust.html) produces identical maps for both the robust and basic GWR types. Any help or guidance you can provide is much appreciated. Thank you!