The webmaster is seeing these pages as duplicates or they see less indexing than they would expect.
John said that the webmaster will need to make sure that their website actually can be rendered for search first. One of the best ways to do this is to use a site query for these specific pages.
It’s important to do this because the testing tools have much stricter guidelines regarding how fast a server should respond compared to how Google actually acts.
It’s possible that the testing tool says that it’s not working when, in fact, it actually does work properly on Google itself.
This is important to keep in mind.
This conversation occurs at approximately 20:58 in the video: