stuck while booting since 20.04.3 LTS upgrade

After the upgrade to 20.04.3 LTS booting doesn't work.

In the booting process (using the latest kernel) the computer stuck,
showing a purple screen:
                              UBUNTU 20.04
                               . . . . .

(sometimes the dots indicating "i'm busy" by changing color, sometimes the dots are frozen)

To get the Computer running i have to try it many times, booting with different kernels - if the booting process is successful it shows the familiar black screen with the ubuntu logo and the animated circle.

I have already repaired the grub (option in recovery mode) and after that re installed ubuntu completely, but the (unsteady) booting problem still appears.

Last time i could start the Computer it worked with the 5.3.0-18-generic kernel.
These are the Kernels installed on my Computer:

ii linux-image-5.3.0-18-generic 5.3.0-18.19+1 amd64 Signed kernel image generic

ii linux-image-5.4.0-89-generic 5.4.0-89.100 amd64 Signed kernel image generic

ii linux-image-generic 5.4.0.89.93 amd64 Generic Linux kernel image

I used ubuntu 19.04 for 2 years on this computer (HP dv 6, i7-2630qm 64bit) having no problems.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubuntu-release-upgrader-core 1:20.04.36
ProcVersionSignature: Ubuntu 5.3.0-18.19-generic 5.3.1
Uname: Linux 5.3.0-18-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.21
Architecture: amd64
CasperMD5CheckResult: skip
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Mon Nov 8 20:20:32 2021
InstallationDate: Installed on 2021-11-07 (1 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
Symptom: dist-upgrade
UpgradeStatus: Upgraded to focal on 2021-11-07 (1 days ago)
VarLogDistupgradeTermlog: