13: Permission Denied During Updates

Hello,

I'm trying to run a simple apt-get update && apt-get upgrade -y command, however, when I run that command, I get this:

apt-get update && apt-get upgrade -y
Reading package lists… Done
E: Could not open lock file /var/lib/apt/lists/lock - open (13: Permission denied)
E: Unable to lock directory /var/lib/apt/lists/
W: Problem unlinking the file /var/cache/apt/pkgcache.bin - RemoveCaches (13: Permission denied)
W: Problem unlinking the file /var/cache/apt/srcpkgcache.bin - RemoveCaches (13: Permission denied)

When I run the same command with sudo prefix I get more progress, but still no luck. Her's the output that I get when I run sudo apt-get update && apt-get upgrade -y:

[sudo] password for example_user:
Hit:1 http://mirrors.linode.com/ubuntu eoan InRelease
Get:2 http://mirrors.linode.com/ubuntu eoan-updates InRelease [97.5 kB]
Get:3 http://mirrors.linode.com/ubuntu eoan-backports InRelease [88.8 kB]
Get:4 http://security.ubuntu.com/ubuntu eoan-security InRelease [97.5 kB]
Get:5 http://mirrors.linode.com/ubuntu eoan-updates/main i386 Packages [76.2 kB]
Get:6 http://mirrors.linode.com/ubuntu eoan-updates/main amd64 Packages [99.7 kB]
Get:7 http://mirrors.linode.com/ubuntu eoan-updates/main Translation-en [37.0 kB]
Get:8 http://mirrors.linode.com/ubuntu eoan-updates/main amd64 c-n-f Metadata [1,792 B]
Get:9 http://mirrors.linode.com/ubuntu eoan-updates/restricted amd64 Packages [5,140 B]
Get:10 http://mirrors.linode.com/ubuntu eoan-updates/restricted Translation-en [1,188 B]
Get:11 http://mirrors.linode.com/ubuntu eoan-updates/universe i386 Packages [39.2 kB]
Get:12 http://mirrors.linode.com/ubuntu eoan-updates/universe amd64 Packages [41.6 kB]
Get:13 http://mirrors.linode.com/ubuntu eoan-updates/universe Translation-en [21.7 kB]
Get:14 http://mirrors.linode.com/ubuntu eoan-updates/universe amd64 c-n-f Metadata [1,736 B]
Get:15 http://mirrors.linode.com/ubuntu eoan-updates/multiverse i386 Packages [1,340 B]
Get:16 http://mirrors.linode.com/ubuntu eoan-updates/multiverse amd64 Packages [1,172 B]
Get:17 http://mirrors.linode.com/ubuntu eoan-backports/universe amd64 Packages [2,940 B]
Get:18 http://mirrors.linode.com/ubuntu eoan-backports/universe i386 Packages [2,944 B]
Get:19 http://mirrors.linode.com/ubuntu eoan-backports/universe amd64 c-n-f Metadata [188 B]
Get:20 http://security.ubuntu.com/ubuntu eoan-security/main amd64 Packages [70.9 kB]
Get:21 http://security.ubuntu.com/ubuntu eoan-security/main i386 Packages [47.6 kB]
Get:22 http://security.ubuntu.com/ubuntu eoan-security/main Translation-en [26.9 kB]
Get:23 http://security.ubuntu.com/ubuntu eoan-security/main amd64 c-n-f Metadata [1,456 B]
Get:24 http://security.ubuntu.com/ubuntu eoan-security/restricted amd64 Packages [5,140 B]
Get:25 http://security.ubuntu.com/ubuntu eoan-security/restricted Translation-en [1,188 B]
Get:26 http://security.ubuntu.com/ubuntu eoan-security/universe amd64 Packages [30.1 kB]
Get:27 http://security.ubuntu.com/ubuntu eoan-security/universe i386 Packages [27.9 kB]
Get:28 http://security.ubuntu.com/ubuntu eoan-security/universe Translation-en [16.1 kB]
Get:29 http://security.ubuntu.com/ubuntu eoan-security/universe amd64 c-n-f Metadata [1,448 B]
Get:30 http://security.ubuntu.com/ubuntu eoan-security/multiverse amd64 Packages [1,172 B]
Get:31 http://security.ubuntu.com/ubuntu eoan-security/multiverse i386 Packages [1,340 B]
Fetched 849 kB in 3s (279 kB/s)
Reading package lists… Done
E: Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied)
E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?

I'm not using a root account, but the "example_user" is part of sudo group.

Just for kicks, I went ahead and logged on using root account and ran the apt-get update && apt-get upgrade -y command again. Here's the output I got:

Hit:1 http://mirrors.linode.com/ubuntu eoan InRelease
Hit:2 http://mirrors.linode.com/ubuntu eoan-updates InRelease
Hit:3 http://mirrors.linode.com/ubuntu eoan-backports InRelease
Hit:4 http://security.ubuntu.com/ubuntu eoan-security InRelease
Reading package lists… Done
Reading package lists… Done
Building dependency tree
Reading state information… Done
Calculating upgrade… Done
The following packages have been kept back:
linux-generic linux-headers-generic linux-image-generic
The following packages will be upgraded:
intel-microcode klibc-utils libklibc linux-firmware
4 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
Need to get 85.5 MB of archives.
After this operation, 611 kB of additional disk space will be used.
Get:1 http://mirrors.linode.com/ubuntu eoan-updates/main amd64 klibc-utils amd64 2.0.6-1ubuntu3 [95.7 kB]
Get:2 http://mirrors.linode.com/ubuntu eoan-updates/main amd64 libklibc amd64 2.0.6-1ubuntu3 [41.9 kB]
Get:3 http://mirrors.linode.com/ubuntu eoan-updates/main amd64 linux-firmware all 1.183.2 [83.0 MB]
Get:4 http://mirrors.linode.com/ubuntu eoan-updates/main amd64 intel-microcode amd64 3.20191112-0ubuntu0.19.10.2 [2,406 kB]
Fetched 85.5 MB in 2s (55.5 MB/s)
(Reading database … 106177 files and directories currently installed.)
Preparing to unpack …/klibc-utils_2.0.6-1ubuntu3_amd64.deb …
Unpacking klibc-utils (2.0.6-1ubuntu3) over (2.0.6-1ubuntu2) …
Preparing to unpack …/libklibc_2.0.6-1ubuntu3_amd64.deb …
Unpacking libklibc:amd64 (2.0.6-1ubuntu3) over (2.0.6-1ubuntu2) …
Preparing to unpack …/linux-firmware_1.183.2_all.deb …
Unpacking linux-firmware (1.183.2) over (1.183.1) …
Preparing to unpack …/intel-microcode_3.20191112-0ubuntu0.19.10.2_amd64.deb …
Unpacking intel-microcode (3.20191112-0ubuntu0.19.10.2) over (3.20190918.1ubuntu1) …
Setting up linux-firmware (1.183.2) …
update-initramfs: Generating /boot/initrd.img-5.3.0-19-generic
I: The initramfs will attempt to resume from /dev/sdb
I: (UUID=76696225-bd13-49b4-ad48-770c55aa8769)
I: Set the RESUME variable to override this.
update-initramfs: Generating /boot/initrd.img-5.3.0-18-generic
I: The initramfs will attempt to resume from /dev/sdb
I: (UUID=76696225-bd13-49b4-ad48-770c55aa8769)
I: Set the RESUME variable to override this.
Setting up intel-microcode (3.20191112-0ubuntu0.19.10.2) …
update-initramfs: deferring update (trigger activated)
intel-microcode: microcode will be updated at next boot
Setting up libklibc:amd64 (2.0.6-1ubuntu3) …
Setting up klibc-utils (2.0.6-1ubuntu3) …
Processing triggers for initramfs-tools (0.133ubuntu10) …
update-initramfs: Generating /boot/initrd.img-5.3.0-19-generic
I: The initramfs will attempt to resume from /dev/sdb
I: (UUID=76696225-bd13-49b4-ad48-770c55aa8769)
I: Set the RESUME variable to override this.

Does anyone know what it wants and why a user that is part of sudo group is getting permission denied to a directory?