Activating Reap once the transition from Reaper Form to Human Form has begun will prevent the character from moving until they use a teleport ability. This likely requires some degree of latency to reproduce (I have 36ms). However, it may just be that reap is allowed to be activated in an invalid state rather than a latency issue. Attached gif demonstrates the movement failure and subsequent recovery with a teleport.
Player.log (2.6 MB)