Can't add new media files

[rvmeush]

I am using a Docker version of Jellyfin 10.9.6 on my Synology NAS.   I find that when I add new files to the Video media folder they are not showing up when I browse my Jellyfin server online.    I'm not sure when this started happening, but I also discovered that the Music folder I had in the Media directory has disappeared in Jellyfin.  The Music folder still exists when I browse the media directory on my NAS, but Jellyfin doesn't recognize it anymore.

Can any offer advice for restoring correct operation or at least how to diagnose the problem?

Thanks.