Haven't noticed that myself, would you mind posting your class / race / CHA based proficiences? Maybe some of us can see if we can replicate it?
The more data on a bug they have, the better. Also, when you mouse over things that involve Charisma, does it state something like 1d20+2 Charisma check. Don't recall the exact wording. It could just be a bug in the rolling system, or it could be a bug with Charisma as a whole.
