Ubuntu Installer crashes on restart

[Alex]

Problem:
1. After fresh install of Ubuntu 20.04 from USB drive
2. Presented "Continue test Ubuntu" or "Restart"
3. Selected Restart
4. System does not restart, "Remove USB media" is not shown.
5. Stuck with dark screen.

Workaround
1. manually turn off computer or remove USB media.
2. Boot system.
3. System starts.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity (not installed)
ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30
Uname: Linux 5.4.0-29-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Fri May 8 08:36:56 2020
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed initrd=/casper/initrd quiet splash --- maybe-ubiquity
InstallationDate: Installed on 2020-05-04 (4 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
Symptom: installer
UpgradeStatus: No upgrade log present (probably fresh install)