At first I thought it was just in act 3, not the case. Then I thought it was a revenge spamming issue...also not the case. I can't say for sure if it only happens with 5 stacks of NV, because it's so sporadic I always just seem to have 5 stacks when it happens.
It appears to be the charge, or for the monk the dashing strike, making the character get glitched. It also seems to occur when trying to charge around an obstacle instead of in a straight path. My guess is the character is getting stuck while trying to path around the object during the charge. Can't verify that however...get so frustrated when it happens I forget all of the details such as mob affixes and combat situations.
Please find an answer for this issue.