I solved it!
You have to update ComfyUI, and recreate the node.
Updating wasn't as simple as running update_comfyui.bat; I also had to handle a merge conflict.
I asked ChatGPT, and it gave me two commands to run from the command prompt in the \ComfyUI folder:
git reset --hard origin/master
After that, the update_comfyui.bat worked again (though I'm not sure it was necessary to run it afterwards).
And as mentioned: Recreate the Load ControlNet Model node after the update and restart of ComfyUI - it seem to have changed.
That's it! :)