So, I have been fighting this issue for over 3 days now, and a couple of days ago I went to Reddit on this. Now I have more information regarding this issue. So, my animation only moves in the animation preview, but in a blueprint/animation bp it remains on the first frame/pose. The skeletons/skeletal meshes are the same between character blueprint and the animation blueprint. I am really having issues figuring this out, and without animations, a game is not a game. It’s just character sliding on the mesh. The thing unreal about the engine is how f*cking unreal these bugs can be… Please help. Thanks in advance! 
can’t say without seeing your anim bp, but i bet you don’t have it set up right.
Hi, Are you using a single animation or an animBP? I guess you already tried debugging your animation in real time?
If not, while playing, select the instance of the animBP from the dropdown menu, and see where is the issue in the Anim Graph.
Maybe your character is stuck on a state transition or something.