Range indicator isn't working as its suppose too

so i recently did this to help with my AA's and what i noticed (when playing with azir and veigar who i only tested this with) that they AA outside their range indicator, i don't know if this has to do with how big minion hit boxes actually are (they seem big to be outside the indicator range but still be able to get hit with AA's) or the indicator range is incorrect. Is this intended? (i played on blue side both times)