Here are the list of bugs that have been reported before but not worked on since one year of beta gameplay.
Bug 1 - If you're running diagonally and if your opponent is running diagonally, and if you get shot a jutsu like earth spikes / fire walls/ water bullets / vacuum palms etc. your sub will break, you will be put in front of your opponent and take damage.
Bug 2 - If you cast Firewall while moving diagonally, it will have a + shaped hitbox instead of a straight | line.
Annoyance 3 (not a bug but very annoying feature due to self-stun applied by the system to prevent rubberband) - When your opponent cast mud river and you try to move around to respond, you will be put in a self-stun due to knockback which applies rubberband.
If you have any pvp bug to report that you know of, please do. Make NiN at least a bit better place.