System freeze

When the laptop is left unattended until the session is locked and screen is off, after a while the whole system freeze/crash and the only way is to hard reset.
Please check the attached dmesg.out.2 file for more details.

This issue happens only when the integrated graphics is the primary GPU and nvidia is used as "on demand".
But if nvidia is the primary GPU, then there no problem at all.

Also it doesn't happen in Wayland session, only with Xorg.

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: xorg 1:7.7+22ubuntu1
ProcVersionSignature: Ubuntu 5.11.0-22.23-generic 5.11.21
Uname: Linux 5.11.0-22-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
.proc.driver.nvidia.capabilities.gpu0: Error: path was not a regular file.
.proc.driver.nvidia.capabilities.mig: Error: path was not a regular file.
.proc.driver.nvidia.gpus.0000.58.00.0: Error: path was not a regular file.
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.suspend: suspend hibernate resume
.proc.driver.nvidia.suspend_depth: default modeset uvm
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 465.27 Thu Apr 22 23:21:03 UTC 2021
 GCC version: gcc version 10.3.0 (Ubuntu 10.3.0-1ubuntu1)
ApportVersion: 2.20.11-0ubuntu65.1
Architecture: amd64
CasperMD5CheckResult: pass
CompositorRunning: None
Date: Sun Jun 27 19:46:12 2021
DistUpgraded: Fresh install
DistroCodename: hirsute
DistroVariant: ubuntu
DkmsStatus:
 nvidia, 465.27, 5.11.0-22-generic, x86_64: installed
 virtualbox, 6.1.18, 5.11.0-18-generic, x86_64: installed
 virtualbox, 6.1.18, 5.11.0-22-generic, x86_64: installed
ExtraDebuggingInterest: Yes
GpuHangFrequency: Several times a day
GpuHangReproducibility: Occurs more often under certain circumstances
GpuHangStarted: Immediately after installing this version of Ubuntu
GraphicsCard:
 Intel Corporation TigerLake GT2 [Iris Xe Graphics] [8086:9a49] (rev 01) (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Iris Xe Graphics [1043:1e6f]
   Subsystem: ASUSTeK Computer Inc. TU117M [GeForce MX450] [1043:1e6f]
InstallationDate: Installed on 2021-06-04 (22 days ago)
InstallationMedia: Ubuntu 21.04 "Hirsute Hippo" - Release amd64 (20210420)
MachineType: ASUSTeK COMPUTER INC. ZenBook UX435EG_UX435EG
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.11.0-22-generic root=/dev/mapper/vgubuntu-root ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
Title: Xorg freeze
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/08/2021
dmi.bios.release: 5.19
dmi.bios.vendor: American Megatrends International, LLC.
dmi.bios.version: UX435EG.305
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: UX435EG
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK COMPUTER INC.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInternational,LLC.:bvrUX435EG.305:bd04/08/2021:br5.19:svnASUSTeKCOMPUTERINC.:pnZenBookUX435EG_UX435EG:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnUX435EG:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0:
dmi.product.family: ZenBook
dmi.product.name: ZenBook UX435EG_UX435EG
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK COMPUTER INC.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.104-1build1
version.libgl1-mesa-dri: libgl1-mesa-dri 21.0.1-2
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.11-1ubuntu1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200714-1ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.17-1