[GAMEPLAY] Vladimir being unable to target enemies.

As Vladimir, you become unable to target enemies such as minions, towers, and champions. The only way to fix this that I've experienced is to port back to base. The only consistent cause I've noticed is using Vlad's Q and then pool in quick succession, afterwards you can't target any enemies. I've had it happen four times in four different games today, but never had it happen before patch 6.5.