Apt periodic doesn't work

[Jayson Willson <jaysonwillson245@gmail.com>]

Hello! I use Debian Stable. Recently I have installed 
unattended-upgrades package, so as to have apt lists updated and 
possible upgrades downloaded automatically (while I do not want them to 
be installed automatically). However, though I think I have configured 
everything correctly, apt doesn't update package lists automatically (I 
have been using my computer for three days since then and update did not 
take place).

Here is my /etc/apt/apt.conf.d/20auto-upgrades:
http://ix.io/TvB
Here is my /etc/apt/apt.conf.d/50unattended-upgrades:
http://ix.io/TvC
Here is my apt-config dump output:
http://ix.io/TvD
Here is my /etc/cron.daily/apt:
http://ix.io/TvE
According to systemctl status cron, cron is running.
Could you please help me with this problem? Thanks in advance.

--
Yours sincerely, Jayson Willson