Hi Vladimir, Ben,
Thanks for your quick reply. I found the work around: I need to exit Radzen and restart it after having made the change, and then it shows. My guess is that the refresh button next to the drop down that lets the user select the custom method is not working. I made a small demo video of the issue if this can help.
Radzen was already an impressive product a year or so ago when I tried it, but it has matured significantly since and the Blazor version is quite amazing, what a great job you guys are doing, thanks!