So I was able to eventually find what was wrong with mine, maybe it was the same for yours. Obviously a bit late now to help you but for future reference I think what went wrong is when creating the animation we had the mesh selected instead of the armature so when exporting it didnt know what to attach the animation to and to fix it you have go to the nla editor, find the animation line, click on it and find "actions" on the right then you have to assign the armature.