I don't really know how network stuff works in this game, but a lot of people seem to be complaining about lag, especially when kiting. I guessing that's because when they dodge an enemy, they will see on their screen that they are out of range of an attack, however because there is a delay before the information of the player running from one position to another is sent to the server, the server will think that the player is still in range of the attack and therefore should take damage.
In other multiplayer games, the same thing happens because lag is unavoidable. For example in TF2, let's say, somebody is chasing you while you are backpedaling. You both have your melee weapons out and take swings at each other, however only his hits register. The game makes you take damage from where you are and deal damage from where you were. That is because while you know your real position, where you see yourself on your screen, the server only knows your delayed position. How outdated your position is to the server depends on your ping. If you have 200 ping, then the server only takes into account your position from 0.2 seconds ago. 50 ping means a 0.05 second delay, 1000 ping means a 1 second delay, etc.
TF2 actually uses collision hulls for melee hit registration instead of hitboxes, but "hitbox" is a more familiar term for most players. Also here's the video which made me learn this.
Currently, DST makes you take damage from where you were, even if the attack animation of the mob doesn't match up. This usually gives the illusion that mobs have doubled attack range and quicker attack wind-ups, which I can understand is frustrating. What if the game only let you take damage from where you are? This means the game only checks if you were in attack range or not when the mob performs its attack on your own screen instead of the server. I believe that would be a more reliable way to decide if a player should take damage or not.
Again, I don't know how network stuff works in this game. If somebody with proper knowledge can provide a better solution, then that would be delightful.
Note that I'm not saying I'm completely correct, this is all just guesses based on my limited knowledge. Also, don't laugh at the terrible drawings.