What is the correct template filename? I created a new content type using Drupal 8 with the machine name "reviews." I thought that by duplicating the original content type template file, node.html.twig, and renaming it node--reviews.html.twig, I would be able to override the original template.
However, any new change is not reflected when I open any of my review pages. I have already cleared the cache.

What is the correct way to override the default template file?
node--reviews.html.twig is correct. In my current theme, I have node--staff.html.twig and node--video.html.twig; they work perfectly fine. It could be a cache issue or probably a spelling issue.