Cannot upgrade from ubuntu 18.04.5 to 20.04

[Jay]

When attempting to run the upgrade in command line, I receive the error below.
I tried upgrading from kernel 4.15 to 5.4, still get the same error.
Found a USB realtek wifi module in dkms holding and completely removed dkms but still encounter the upgrade issue.

Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done

Calculating the changes

Calculating the changes

Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade.

If none of this applies, then please report this bug using the
command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal. If
you want to investigate this yourself the log files in
'/var/log/dist-upgrade' will contain details about the upgrade.
Specifically, look at 'main.log' and 'apt.log'.

Restoring original system state

Aborting
Reading package lists... Done
Building dependency tree
Reading state information... Done

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.40
ProcVersionSignature: Ubuntu 5.4.0-52.57~18.04.1-generic 5.4.65
Uname: Linux 5.4.0-52-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.18
Architecture: amd64
CrashDB: ubuntu
Date: Wed Nov 4 12:26:24 2020
InstallationDate: Installed on 2020-06-19 (138 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2020-11-04 (0 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.