kdump does not trigger for hwe kernel (works for 5.4)

I can not trigger a kdump with my installed hwe kernel (5.8) on 20.04. 5.4 does work.

sudo kdump-config show
DUMP_MODE: kdump
USE_KDUMP: 1
KDUMP_SYSCTL: kernel.panic_on_oops=1
KDUMP_COREDIR: /var/crash
crashkernel addr: 0x98000000
   /var/lib/kdump/vmlinuz: symbolic link to /boot/vmlinuz-5.8.0-44-generic
kdump initrd:
   /var/lib/kdump/initrd.img: symbolic link to /var/lib/kdump/initrd.img-5.8.0-44-generic
current state: ready to kdump

kexec command:
  /sbin/kexec -p --command-line="BOOT_IMAGE=/boot/vmlinuz-5.8.0-44-generic root=UUID=2c41957a-476a-4416-bab8-9aa718afdf5c ro quiet splash vt.handoff=7 reset_devices systemd.unit=kdump-tools-dump.service nr_cpus=1 irqpoll nousb ata_piix.prefer_ms_hyperv=0" --initrd=/var/lib/kdump/initrd.img /var/lib/kdump/vmlinuz

dmesg | grep crash
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-5.8.0-44-generic root=UUID=2c41957a-476a-4416-bab8-9aa718afdf5c ro quiet splash crashkernel=384M-2G:64M,2G-:1G vt.handoff=7
[ 0.000000] kexec: Reserving the low 1M of memory for crashkernel
[ 0.000000] Reserving 1024MB of memory at 2432MB for crashkernel (System RAM: 16337MB)
[ 0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.8.0-44-generic root=UUID=2c41957a-476a-4416-bab8-9aa718afdf5c ro quiet splash crashkernel=384M-2G:64M,2G-:1G vt.handoff=7
[ 0.599000] crashkernel=384M-2G:64M,2G-:1G
[ 4.153854] pstore: Using crash dump compression: deflate

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: linux-image-5.8.0-44-generic 5.8.0-44.50~20.04.1
ProcVersionSignature: Ubuntu 5.8.0-44.50~20.04.1-generic 5.8.18
Uname: Linux 5.8.0-44-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Wed Feb 24 00:00:29 2021
InstallationDate: Installed on 2018-12-01 (815 days ago)
InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.3)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: linux-signed-hwe-5.8
UpgradeStatus: Upgraded to focal on 2020-04-25 (304 days ago)