Updates via Software Updater after release upgrade to Focal prompt user to run Partial Upgrade

After completing release upgrade from Eoan to Focal as a devel release without errors, subsequent updates via Software Updater show a window that prompts the user for a Partial Upgrade, stating "Not all updates can be installed.

The user can then either select Partial Upgrade or Continue. Selecting Continue may or may not upgrade a portion of packages listed (it may simply state "The software on this computer is up to date"). Selecting Partial Upgrade requires the user to authenticate, and then prompts the user to Start Upgrade, with the question "Do you want to start the upgrade?" as well as details of packages removed, new packages installed, and packages upgraded. Selecting Start Upgrade installs, upgrades, and removes packages.

Ubuntu Version: 20.04 Focal Fossa (development branch)
Package version: do-release-upgrade 20.04.9, apt 1.9.8 (amd64)
Expected behavior: User not prompted for Partial Upgrade after release upgrade
What happened: User prompted for Partial Upgrade after release upgrade

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubuntu-release-upgrader-core 1:20.04.9
ProcVersionSignature: Ubuntu 5.4.0-12.15-generic 5.4.8
Uname: Linux 5.4.0-12-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu16
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Tue Feb 4 09:00:56 2020
InstallationDate: Installed on 2018-09-26 (495 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
Symptom: release-upgrade
UpgradeStatus: No upgrade log present (probably fresh install)
VarLogDistupgradeTermlog: