"Random" Shield Charging

Sometimes when there are a lot of mobs around I somehow Shield Charge to a location which I have not clicked at. At least sometimes there are no mobs at this location nor do any mobs appear afterwards at this location. I use lockstep mode and 'attack in place' for Shield Charge. I do not remember this happening (at least not very frequently) before Flashback but I cant be sure as in Flashback there are generally more mobs around which (I think) is a necessary condition for it to appear.
These "random" Shield charges usually (possibly always) are at maximum distance.
The bug may also appear with other skills but I am not sure about it as its much harder to be sure its not me misplacing the mouse cursor a bit.
This has happend quite often now so I am "sensitized" to it so its not due to me accidentally moving the cursor to a random spot or sth. I have seen very clear instances of this with the cursor never being anywhere near the target location or its extrapolation.

It is possible this is an instance of a much older general bug with user input.

Edit: I now use 'dynamic resolution' with target framerate 10. I never before had it so low. This is the only difference in settings on my side I can think of.