I'm not sure if this is RStudio or my Mac, but it only appears in RStudio and not in other applications. After doing something that changes the screen resolution (e.g. watching a movie, playing a game) the resolution in RStudio changes after exiting the previous acitivity. To resolve it I have to manually reduce the resolution then increase it again.
Is this a "bug" in RStudio or does it have to do with some of my settings?