The index is only kept up to date as long as you use Synology's „official“ interfaces (ftp, smb, etc.) for adding/removing media files. Whenever you add/remove files manually using the command line you have to fix the index using synoindex.
因为我用aria2下载 下载结束可以调用脚本 我在脚本里面加上 synoidex -a filename 就解决了
更新下 给大家做个参考