Creating a custom AI character

Hi, I have created a working behavior tree for my ai using the provided Mannequin and third person animBP. When I try to replace the mannequin with a custom character I created with Adobe and animated with Mixamo, the character just slides around and will not play its animBP. I created an animBP idle, walk, run and a blendspace for the character, what am I missing?
Thanks,
Patrick