Generative Fill - "More Properties" not working

It's been a little while since I've used this feature, but I recall it having a few extra options such as how much to let the existing picture influence the generated picture, or how closely it should stick to the area you've selected. 

I don't seem to have these any more. I do have an option in the contextual toolbar for "more properties" but it doesn't seem to do anything. Do I have a problem? Or is this a feature that was removed at some point?