When i was learning UE4 with the third person blueprints tutorial, the FBX files provided in the tutorial were quite choppy. It was mainly the Run,Walk and jump loop that were choppy.
I don’t know how to edit them in Maya either. I tried using ART to try to edit them but i don’t think it allows you to edit motions.
Could you probably post a video, because I think that I have the same problem with my custom anims (suddenly it appeared, but always tought that I made something wrong in my 3d program -> but when I’m at home I will check it again :))