Whenever I am the last sheriff/innocent while attempting to complete the “Sole Survivor” challenge, and I shoot the murderer, it only sometimes updates. I don’t know why this keeps happening, but it is pretty frustrating. I have won around 4 times as sheriff when it was just the murderer, and it has only updated twice.
I have got one. I could imagine that the other player listed among the winners (who must have been a dead innocent spectating as a ghost) caused the bug.