ARAM RNG IS BUGGED

First game- Gets Warwick, rerolls and gets Shaco, plays Shaco, loses. Next game- gets Shaco, rerolls gets Warwick.
I'm not sure if it's a bug or intentional but the RNG seems to follow a pattern where the champion you played with last has a very high chance of being in the next game. Also there seems to be a cesspool of champions which is the "flavor" of the month/week like just today I got Shaco three times even though he is not on the "free list" but Ahri or Diana, I haven't gotten in a long time. Recently I got a lot of Anivias, Galio, Katarina, while last month it was Lissandra, Ryse, Master Yi