Why does some newly-added content not show as recent?

[theguymadmax]

The TV show is a known issue that should be fixed in the upcoming 10.11.0 release: https://github.com/jellyfin/jellyfin/issues/1880

For movies, I've never come across that issue. 

Try Dashboard->Libraries->Display and make sure you have "Use date scanned into the library" for the date added behavior. 

If you use NFO files, then it will use the date in the file, so that could be your issue.