I played a game with a Mason Leader and Citizens in the setup. I was a citizen who was quickly converted into a Mason and remained alive until the end.

Anyways, at one point of the game (I was Mason), the Mason Leader attempted to recruit [Player A]. The next day, the Mason Leader died and Player A was not converted into a Mason. The following day, Player A was killed and revealed to be a Citizen. I do not think that there were any Witches, Bus Drivers or role blockers in the game.

So the possible bug is that Mason Leader cannot recruit properly during the night which he is targetted and killed.