Smart Casting Misbehaving

So my smart casting abilities are acting strangely. Autoactivate abilities like Volibears Q(Rolling Thunder) or lets say Ahri's W, basically abilities that do not use a target to activate, these work perfectly. However targeted or skillshotted abilities are messed up. I am using smart cast, because what player after level 30 isnt using smart cast, its just faster. When i press abilities such as Volibears w which require a single target, i have to quickely tap it(press release fast) for it to work, however if for even a fraction longer the ability will look as if it is normal casting(press key and then select target), however when this happens i have to release the key on the target, meaning im holding volibears w and releasing the key on the target. Now this is even more frustrating with skillshot or area of effect abilities. At the time the first champion i found this issue was... xerath who uses nothing but the above two ability types, skillshot and AOE. A good champion to test my issue though. The same principle for target works with skillshot, i would have to tap the key, if i hold for too long the ability follows my cursor in normal cast form, with the indicators and all. What makes the issue worse is that this problem causes the cast to stop working after being held for one second total. So i cant charge abilities. at all... Xeraths q beam would only go about 75% distance, poppy couldnt charge full R, and same with sion's q, as examples. I have fully uninstalled and reinstalled already.