My Cortana is broken. How to fix?

My Cortana seems very weird on the last few days, it seems she doesn't have "personality" anymore, looks like the native WP speech. She is not singing anymore, when i ask her to sing for example she just says it in the same way the robotic windows phone native speech does. I've already tried to restart my phone and it doesn't work. Does anyone knows how to fix her?

Anyone?

I had the same problem - factory wipe your phone and set it back up. Worked for me.