Broken Role selection/auto fill

Recently it seem like I can "force" people getting autofill as ADC I queue as Support first, ADC second in flex Q (solo or with people and autofill protected most of the time) For my last 7 game if I remove 5 mans premade and premade with adc, it leave me 4 with 3 adc autofill (including one support main autofill as adc when I got adc 2nd so it's clearly BS) Maybe it's time to add the role we don't want to play ? Because some players can play every roles excepted one. Also will we have the 4 mans premade in flex to reduce the waiting time for solo player in flex ?