I found the root of the issue. Ubuntu 19.10, clean installation, no updates.
When the following packages are update: grub-common from version (2.04-1ubuntu12) to (2.04-1ubuntu12.2) grub2-common from version (2.04-1ubuntu12) to (2.04-1ubuntu12.2) grub-efi-amd64-bin from version (2.04-1ubuntu12) to (2.04-1ubuntu12.2) grub-efi-amd64-signed from version (1.128+2.04-1ubuntu12) to (1.128.2+2.04-1ubuntu12.2) grub-pc from version (2.04-1ubuntu12) to (2.04-1ubuntu12.2) grub-pc-bin from version (2.04-1ubuntu12) to (2.04-1ubuntu12.2) I can confirm that these packages are responsible for the reboot issue and trying to install the outdated versions of ubuntu 19.10 on ubuntu 20.04 or 20.10 the laptop restarts normally. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1876753 Title: Thinkpad T430 Power Cycles instead of rebooting To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub/+bug/1876753/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs