Popup shortcut for expression not working

when I type

f(x) = sin(x), exactly like what David did in the attachment below, Grasshopper does not recognize it as a shortcut for expression, it will still think I'm trying to search for a "flip" command (attachment no.2), am I doing anything wrong here?

I have the latest Grasshopper.

I really like the popup shortcuts but without expression the use is supper limited.