>>52090300I know this isn't helpful at all but I'll drop my 2 cents anyway:
Let's assume that the evolution rates are skewed in favor of Violet.
Gamefreak is usually obsessed with symmetric design between versions, so you'd think each version would get 1 of the 2 random rate evolution skewed in their favor.
Continuing with this assumption, this means that 1 of the 2 random rates is skewed towards Scarlet, and yet the rate seems to be abysmal even when skewed. Why would Gamefreak bother to skew the rates if the rates are that low even after?
So I'm betting its unrelated to your version.