It’s a known UE4 bug (Animations from Blender using default settings don't work in UE4 - help fix the Blender FBX exporter - Feedback for Unreal Engine team - Unreal Engine Forums), for now the workaround is to use scene unit scale 0.01 metric. After changing that apply transforms for your rig and mesh. You may need to redo the animations if they stop working (any location keyframes will be way too small).