Kali Linuxの無人アップグレードが機能しない

無人アップグレードが呼び出されないようですapt-get update。無人アップグレードを実行した後は期待どおりapt-get updateに機能しますが、これは無人アップグレードを使用する目的を失います。

$ sudo unattended-upgrade -d
Initial blacklisted packages: 
Initial whitelisted packages: 
Starting unattended upgrades script
Allowed origins are: ['o=Kali,a=kali-rolling']
pkgs that look like they should be upgraded: 
Fetched 0 B in 0s (0 B/s)                                                                               
fetch.run() result: 0
blacklist: []
whitelist: []
No packages found that can be upgraded unattended and no pending auto-removals

編集1：

~$ apt-config dump | grep -i unattended  
APT::Periodic::Unattended-Upgrade "1";
Unattended-Upgrade "";
Unattended-Upgrade::Origins-Pattern "";
Unattended-Upgrade::Origins-Pattern:: "o=Kali,a=kali-rolling";