On the main page, select one of your libraries from the left hand navigation pane, as seen below, like your “TV Shows” library.
Within the library, click on the circular arrow icon in the upper right corner. Manual updating is great if you need to force the update right that second, but for ease of use and really frictionless user experience, you really want to enable automatic updating.
There’s the media itself (like your TV shows), there’s the actual Plex Media Server that manages your media, and then there are the Plex client applications you access the server from via your Apple TV, your i Phone, or other devices.
Because you aren’t directly browsing the folders that contain your videos, it is critically important that Plex Media Server’s database be up to date.
If I go into file view for the same folder, the movies are there. I'm wondering if you went into weather for a little while and came back, would your new additions be waiting?