Potential Auto-Attack bug

I have had SEVERAL occasions how where I will be attacking an enemy minion or champion and need to make a sudden escape but my champion, for seemingly no reason at all, will stop and start Auto Attacking something that happens to be in my path. This will happen regardless of how i choose to move my champion. This bug (if it is one) has cost me several key team fights and (consequently) whole matches, because I was unable to retreat. My mouse often wont be anywhere near the thing I start Auto-attacking. I have also noticed that with certain skillshots, they will not fire off immediately, and if you move your mouse prior to the animation, the direction (etc) of the skillshot will be influenced...however, in this scenario, we are talking fractions of a second. For Example, VelKoz's "W" can be cast while moving, and If I cast the spell and then move my mouse too quickly to guide where Vel is walking,sometimes the skillshot will fire the wrong direction, and diminishing my ability to kite the enemy. This first started occurring when The Harrowing event began. Im not sure if the two issues are related or not.