In the last update the priority was changed so that right click allows you to run away from a target while engaged (ie left click you run to target then right click you run away), until you press shift then you will run towards the target again.. allowing more control over hit and run attacks
In addition, F keys will now (when a skill is ready to cast) prevent you from running the next step and cast the skill first. Previously there was a battle between running and casting the skill and it appeared to randomly do one of the two so you never had full control over casting the skill.
The problem you are describing sounds like the old way it was done, are you up to date?