Visual Studio Code has a setting called "Editor: Definition Link Opens In Peek". This is a checkbox.

If unchecked, CTRL+Click on unambiguous definitions will navigate to the definition. If checked, CTRL+Click will open this definition peeking popover.

I actually came to find it because I wanted to tick it on. I find peeking a convenient way to see a definition together in the reference location (basically a more clunky alternative to a feature which would allow us to expand external definitions inplace).