LUKS decryption fails with certain external monitor

On boot whenever my DELL U2718Q Monitor is connected LUKS Ubuntu partition decryption fails with
```
No key available with this passphrase
```
Password and partition encryption are fine, since decryption works with disconnected Monitor. For decryption to work the Monitor needs to be disconnected before selecting Ubuntu in Grub 2. It can be connected before.

The Ubuntu partition can also be successfully decrypted from another Ubuntu instance with gnome-disks - with monitor connected.

Graphic processor: NVIDIA Corporation TU106GLM [Quadro RTX 3000 Mobile / Max-Q] / Quadro RTX 3000/PCIe/SSE2
GNOME-Version: 3.36.8
Window manager: X11

See also my error description here: https://askubuntu.com/questions/1417485/external-display-sabotages-luks-decryption

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: cryptsetup 2:2.2.2-3ubuntu2.4
ProcVersionSignature: Ubuntu 5.15.0-41.44~20.04.1-generic 5.15.39
Uname: Linux 5.15.0-41-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.24
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Sat Jul 16 19:02:42 2022
InstallationDate: Installed on 2021-05-13 (429 days ago)
InstallationMedia: Ubuntu 20.04.2.0 LTS "Focal Fossa" - Release amd64 (20210209.1)
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: cryptsetup
UpgradeStatus: No upgrade log present (probably fresh install)
cmdline: BOOT_IMAGE=/vmlinuz-5.15.0-41-generic root=UUID=4d833d1d-b74c-4586-8d05-71ffb8230de6 ro resume=UUID=4d833d1d-b74c-4586-8d05-71ffb8230de6 resume_offset=21474836480
crypttab:
 sda6_crypt UUID=bdaa9b82-9a1a-4674-a1e3-e7073031bd95 none luks,discard
 data /dev/sda7 /dev/null tcrypt-veracrypt,tcrypt-keyfile=/some/keyfile