The CodeSweep extension is somehow disabling the built-in VSCode markdown extension.
Steps to reproduce:
- Start VS Code (with the CodeSweep extension disabled)
- Create a simple .MD file with basic content.
- Save the file. On the top right, the icon to show preview in split window shows up:

The shortcut to show the preview works too Command + Shit + V
- Enable the CodeSweep extension
- Go back to the same .MD file and the button to show the preview is gone.

The keyboard shortcut no longer switches to the preview mode.
If you then disable the extension and reload VS Code, the markdown preview extension works again. Something seems to be clashing between the 2 plugins.