Problem with Blendshapes and Animation

Hello everyone,
i created a 3D human model and i added blendshapes to change the appearance of the face for the character customization menu. The blendshapes where working fine but when i tried to play an idle animation i created and imported from blender, that i want to play while the player is customizing the character's appearance, now while the animation is playing the blendshapes don't update. I can't even change the blendshape slider from within the inspector while the animation is playing. Any ideas how to do this?
Thank you in advance.