PBE Shen Taunt/Flash not smooth, possible BUG?

I have seen people playing Shen try and perform this combo as well as tried this myself. It's awkward now. I have successfully landed my taunt/flash and I have seen the enemy walk away then come back. There seems to be a delay.

I have seen a few people streaming and it looked like it didn't even work at all. This may be do to not being used to the animation and they may have missed it by a hair (which in this case his hit box is very small).

I can guarantee that there have been several times where I have taunt/flashed right on the enemy and they literally walked away, then walked back to Shen.