Hmm, random portrait should re-roll the portrait. If it does nothing, almost sounds like the game's built-in random portrait functionality is still at work and not the mod. Or something else is going on. If you edit settings.gd in the mod's folder and change
var debug = false
to
var debug = true
then re-run the game, it should output on the console a bunch of data about portraits it found, and when it tries to randomly assign a portrait, what it's assigning and why.
Gender is a hard rule, and Age is a bit fuzzy, it tries to be a hard rule, but if too few results, it relaxes things a bit. If it's only doing race as a hard rule, that's what the game's default logic does, so sounds like the mod didn't fully apply. When you applied this to the game, was it a fresh extraction of the new version?