The syncing issue is one that I have been tracking down since early 2019 and the introduction of Dino Rotation and the other adjustments that followed it.
So far this is also what I have noticed, that the source of the issue is moving with Keyboard, and everything seems fine while playing with mouse, but as we know, you can't do a PvP using only mouse.
The issue first appeared to be a "Delay in attack" whether by Dino or Weapon, so I kept on reporting this issue to our Developers until finally something was done about it. A new loop mechanism was added, and with intensive boosting to in-game syncing, finally the Delay in attack issue was solved, but a new issue emerged, it is when you click your skills but they are unavailable at the edge of your skill range span. Some attempts of fixing this issue was tried, but it backfired, and situation got even worse. So even further boosting to syncing was issued.
I could say that so far we haven't tackled the real issue here, because we can't see it, or understand why it is happening, but I know one thing for sure, it is related to Keyboard movement keys.
Since I am not a Developer, or even a programmer, I can't promise you of a solution to this issue soon, or give you a date of when it will be solved. All I am saying is that we are aware of this issue & what you are experiencing. Perhaps a clue of why it is happening.
Crazy clicking won't solve the issue, you just need greater endurance as one step further is what it truly takes to activate these skills. I understand that you have to click many times in order to active your skill once it is available. But from my own PvP experience, that have been mostly a mistake. You should retreat, heal, then charge again, until you have close grasp on your opponent. Crazy clicking while having low endurance is pointless as you will never be close enough, even if you appear to be.
I do not say that this is "The Solution" but it is a way to adapt until this issue is fixed.