As you can see in the following images, Insiders syntax highlighting isn't working properly.

Both programs are using the same theme "Dark modern" although I've already tried all the themes and disabling/enabling all extensions with no luck.

Normal behaviour on VSCode:

Behaviour presented by VSCode - Insiders:

I have also tried uninstalling/reinstalling and deleting the user folder in AppData\Roaming\Code - Insiders.

Any help would be appreciated.