Syndra's ult

first of all I understand the mechanics of physics and it makes sense in a real world each orb would hit individually at a time frame dependent on its geographical location from its target. how ever I am not sure if its intentional or not but it seems in a lot of cases this concept of not allowing syndra's full ult dmg to hit all in one chuck or at a faster rate of travel to the target seems to have some problems. the most common I seem to experience is ulting and being murdered before my ult even finishes its own travel time to its target make the rest of my skill set useless (example: ult, spread stunning.) almost impossible without being one shot'd before the ults own animation comes to an end. the second problem I honestly believe is a glitch involving invis. I have noticed from time to time if I ult someone like evelyn or twitch etc. . as they go invis sometimes the orbs wont follow the target and appear to be dumped at the location where the target was before invis. and a couple of times I have questioned weather the misdirected orbs even hit the target after the effect of invis. anyone else suffering these random moments with syndra that seem to be in consist mechanics? or is this something that's intentional Riot?