Hi! Unfortunately, I can't help you that. You should try ask in another place for help.
Even so, I'd still like to try to help.
This only happen with the Calibiri font? Not others?
Does the stutters only occur when a text using that font is shown? or does it happen randomly?
How are you translating? Translator++? or in the Editor itself?
Sorry if the question is very obvious, because, as i said, I can't be of much help.