Random Rebooting After Mint 20 Install

[tiparega]

It happens the same to me with Linux Mint 20. [ as here ] I tried a new kernel, but behaves the same way.
At the beginning, freshly installed, it happened shortly after starting, and then didn't reboot.
Now, it takes more time until first reboot (hours), but continues rebooting after that.

Code: Select all

System:
  Kernel: 5.11.0-37-generic x86_64 bits: 64 compiler: N/A 
  Desktop: Cinnamon 4.6.7 wm: muffin 4.6.3 dm: LightDM 1.30.0 
  Distro: Linux Mint 20 Ulyana base: Ubuntu 20.04 focal 
Machine:
  Type: Desktop Mobo: ASUSTeK model: PRIME X570-P v: Rev X.0x 
  serial: <filter> UEFI: American Megatrends v: 2407 date: 07/01/2020 
CPU:
  Topology: 12-Core model: AMD Ryzen 9 3900X bits: 64 type: MT MCP arch: Zen 
  L2 cache: 6144 KiB 
  flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm 
  bogomips: 182053 
  Speed: 1862 MHz min/max: 2200/3800 MHz boost: enabled Core speeds (MHz): 
  1: 1863 2: 2796 3: 2196 4: 2196 5: 1872 6: 2792 7: 1860 8: 2193 9: 2194 
  10: 2196 11: 2052 12: 2051 13: 1862 14: 3595 15: 2194 16: 2196 17: 2188 
  18: 2194 19: 2194 20: 2195 21: 2192 22: 2194 23: 2188 24: 2195 
Graphics:
  Device-1: NVIDIA TU116 [GeForce GTX 1660 SUPER] vendor: ASUSTeK 
  driver: nvidia v: 470.63.01 bus ID: 08:00.0 chip ID: 10de:21c4 
  Display: x11 server: X.Org 1.20.11 driver: nvidia 
  resolution: 1920x1080~60Hz 
  OpenGL: renderer: NVIDIA GeForce GTX 1660 SUPER/PCIe/SSE2 
  v: 4.6.0 NVIDIA 470.63.01 direct render: Yes 
Audio:
  Device-1: NVIDIA TU116 High Definition Audio vendor: ASUSTeK 
  driver: snd_hda_intel v: kernel bus ID: 08:00.1 chip ID: 10de:1aeb 
  Device-2: AMD Starship/Matisse HD Audio vendor: ASUSTeK 
  driver: snd_hda_intel v: kernel bus ID: 0a:00.4 chip ID: 1022:1487 
  Device-3: CVT . type: USB driver: snd-usb-audio,uvcvideo bus ID: 7-2.3:6 
  chip ID: 1ff7:0501 serial: <filter> 
  Device-4: DisplayLink type: USB driver: cdc_ncm,snd-usb-audio 
  bus ID: 7-2.4.4:8 chip ID: 17e9:4307 serial: <filter> 
  Sound Server: ALSA v: k5.11.0-37-generic 
Network:
  Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
  vendor: ASUSTeK driver: r8169 v: kernel port: f000 bus ID: 04:00.0 
  chip ID: 10ec:8168 
  IF: enp4s0 state: up speed: 1000 Mbps duplex: full mac: <filter> 
  IF-ID-1: br-bbb0e3bba0ca state: down mac: <filter> 
  IF-ID-2: docker0 state: down mac: <filter> 
  IF-ID-3: enx002467358e6e state: down mac: <filter> 
Drives:
  Local Storage: total: 931.52 GiB used: 366.97 GiB (39.4%) 
  ID-1: /dev/nvme0n1 vendor: Corsair model: Force MP600 size: 465.76 GiB 
  speed: 63.2 Gb/s lanes: 4 serial: <filter> rev: EGFM11.3 scheme: GPT 
  ID-2: /dev/sda vendor: Samsung model: SSD 850 EVO 500GB size: 465.76 GiB 
  speed: 6.0 Gb/s serial: <filter> rev: 1B6Q scheme: GPT 
Partition:
  ID-1: / size: 40.45 GiB used: 27.35 GiB (67.6%) fs: ext4 
  dev: /dev/nvme0n1p5 
  ID-2: /home size: 160.82 GiB used: 22.89 GiB (14.2%) fs: ext4 
  dev: /dev/nvme0n1p7 
  ID-3: swap-1 size: 16.00 GiB used: 0 KiB (0.0%) fs: swap 
  dev: /dev/nvme0n1p6 
Sensors:
  System Temperatures: cpu: 48.1 C mobo: N/A gpu: nvidia temp: 31 C 
  Fan Speeds (RPM): N/A gpu: nvidia fan: 25% 
Repos:
  No active apt repos in: /etc/apt/sources.list 
  Active apt repos in: /etc/apt/sources.list.d/docker.list 
  1: deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu focal stable
  Active apt repos in: /etc/apt/sources.list.d/google-cloud-sdk.list 
  1: deb [signed-by=/usr/share/keyrings/cloud.google.gpg] http://packages.cloud.google.com/apt cloud-sdk main
  Active apt repos in: /etc/apt/sources.list.d/google-earth-pro.list 
  1: deb [arch=amd64] http://dl.google.com/linux/earth/deb/ stable main
  Active apt repos in: /etc/apt/sources.list.d/home:ungoogled_chromium.list 
  1: deb http://download.opensuse.org/repositories/home:/ungoogled_chromium/Ubuntu_Focal/ /
  Active apt repos in: /etc/apt/sources.list.d/official-package-repositories.list 
  1: deb http://packages.linuxmint.com ulyana main upstream import backport #id:linuxmint_main
  2: deb http://archive.ubuntu.com/ubuntu focal main restricted universe multiverse
  3: deb http://archive.ubuntu.com/ubuntu focal-updates main restricted universe multiverse
  4: deb http://archive.ubuntu.com/ubuntu focal-backports main restricted universe multiverse
  5: deb http://security.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse
  6: deb http://archive.canonical.com/ubuntu/ focal partner
  Active apt repos in: /etc/apt/sources.list.d/skype-stable.list 
  1: deb [arch=amd64] https://repo.skype.com/deb stable main
  Active apt repos in: /etc/apt/sources.list.d/spotify.list 
  1: deb http://repository.spotify.com stable non-free
  Active apt repos in: /etc/apt/sources.list.d/teams.list 
  1: deb [arch=amd64] https://packages.microsoft.com/repos/ms-teams stable main
Info:
  Processes: 406 Uptime: 1h 39m Memory: 31.27 GiB used: 2.51 GiB (8.0%) 
  Init: systemd v: 245 runlevel: 5 Compilers: gcc: 9.3.0 alt: 9 
  clang: 10.0.0-4ubuntu1 Shell: bash v: 5.0.17 running in: gnome-terminal 
  inxi: 3.0.38 

[SMG]

At the beginning, freshly installed, it happened shortly after starting, and then didn't reboot.
Now, it takes more time until first reboot (hours), but continues rebooting after that.

Welcome to the forum, tiparega.

Have you noticed whether this seems to be more likely to happen when the system is idle or when you are doing certain tasks? If it is while you are working at the computer, what types of work are you doing when it happens.

We would probably need to check logs to determine what is happening, but we would need a better idea of when it happens to know which specific logs to check.

Also, are you running the most recent BIOS/UEFI available for your computer? When I checked PRIME X570-P BIOS & FIRMWARE it looked to me like there have been quite a few updates which list "improve system performance" as a reason for the update.

Machine:
Type: Desktop Mobo: ASUSTeK model: PRIME X570-P v: Rev X.0x
serial: <filter> UEFI: American Megatrends v: 2407 date: 07/01/2020