[vmwgfx] Screen resolution change not possible (AMD/VirtualBox)

I installed Kubuntu 20.10 in VirtualBox. It is not possible to set the initial resolution (800x600) to a higher one. If you do so, the screen resolution changes back to 800x600 after 1-2 seconds.

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
ApportVersion: 2.20.11-0ubuntu43
Architecture: amd64
BootLog: Error: [Errno 13] Keine Berechtigung: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: KDE
Date: Tue Aug 4 18:05:56 2020
DistUpgraded: Fresh install
DistroCodename: groovy
DistroVariant: ubuntu
ExtraDebuggingInterest: I just need to know a workaround
GraphicsCard:
 VMware SVGA II Adapter [15ad:0405] (prog-if 00 [VGA controller])
   Subsystem: VMware SVGA II Adapter [15ad:0405]
InstallationDate: Installed on 2020-08-04 (0 days ago)
InstallationMedia: Kubuntu 20.10 "Groovy Gorilla" - Alpha amd64 (20200804)
Lsusb:
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 Bus 002 Device 002: ID 80ee:0021 VirtualBox USB Tablet
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Lsusb-t:
 /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ohci-pci/12p, 12M
     |__ Port 1: Dev 2, If 0, Class=Human Interface Device, Driver=usbhid, 12M
 /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/12p, 480M
MachineType: innotek GmbH VirtualBox
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-42-generic root=/dev/mapper/vgkubuntu-root ro quiet splash
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/01/2006
dmi.bios.vendor: innotek GmbH
dmi.bios.version: VirtualBox
dmi.board.name: VirtualBox
dmi.board.vendor: Oracle Corporation
dmi.board.version: 1.2
dmi.chassis.type: 1
dmi.chassis.vendor: Oracle Corporation
dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:rvnOracleCorporation:rnVirtualBox:rvr1.2:cvnOracleCorporation:ct1:cvr:
dmi.product.family: Virtual Machine
dmi.product.name: VirtualBox
dmi.product.version: 1.2
dmi.sys.vendor: innotek GmbH
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.102-1
version.libgl1-mesa-dri: libgl1-mesa-dri 20.1.4-1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.8-2ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200714-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1