This change just got merged last night, but we greatly minimized the chars that cause css code hints to popup, which no longer includes (white) space. Now, they don't show up until you start typing a property name. Since you already typed a char, then the initial list is already filtered.

And, of course, you can always explicitly show the list using Ctrl-space.

So, you might want to change this to be more consistent (i.e. check for a-z and a few other key chars) with the other css code hinting.