Beat both campaigns on Hard, but can't play as Arcee

[SgtFuzzyGhost]

As the title says, I've been both campaigns on the highest difficulty, but when I go into Autobot chassis selection for the scout, Arcee does not appear.

I may have fudged it when restarting the level to get all the Decepticon symbols, but the game popped the achievement for the effort. Plus, I can play as Slipstream.

Thinking of playing the last level on Easy (hopefully not the entire campaign) so that I can finally unlock the character. Any other suggestions though?