Create DropDown Helper Gives Unknown Command Error


as per title, when I try to create a helper and choose DropDown as the type, no matter what name and options I give it when I save, it shows “Unknown Command” in red above the helper configuration window.

Anyone have any ideas what’s up and / or how I can resolve? I can’t see anything in the core logging. Is there a way to add debug logging for the helpers?

HA 2023.3.6