You can make it stop yourself: in Visual Studio 2019, go to menu, TOOLS, Options, Text Editor, C/C++, Code Style, Formatting, Spacing, Spacing for braces, and uncheck "Insert space within braces of uniform initialisation and initialiser lists". You will also find more options that can be adjusted to your personal needs.
To reformat the existing code after these changes, press <Ctr+E, D>.