If UI elements do not honor your Windows system DPI setting, particularly in high-DPI or mixed DPI environments, update font settings in the options dialog of Visual Studio. Set both font and size:
Tools | Options | Environment | Fonts and Colors | Show settings for: Environment
Tools | Options | Environment | Fonts and Colors | Show settings for: Statement Completion
Change font to Segoe UI and size to 9. (Do leave set to default/automatic/blank.)
Restart Visual Studio.