I am new to linux, tried reading other post cannot find similar situation, thank you for you help and patience in advance.
I've set up a dual-boot system with Windows 11 and Kubuntu, each installed on a separate disk.(as in image)
I installed the bootloader on the EFI system file of Linux, which has a size of 977 MB. Furthermore, I created partitions for swap, root, and opt.
Disk 1 is linux:
Initially, GRUB loaded without any issues. However, I encountered ACPI issues and made some adjustments to the GRUB settings. Specifically, I added the following lines:
GRUB_CMDLINE_LINUX_DEFAULT="quite splash processor.max_cstate=5 rcu_nocbs=0-11" GRUB_CMDLINE_LINUX="noacpi nomodeset"
These modifications allowed the system to reboot successfully. However, after some recent updates, GRUB is not visible.
Today after automatic memory test, the laptop automatically booted into Windows. I checked the BIOS settings, but there was no sign of the Linux option, and GRUB did not appear either, although the partitions remained visible.
What can I do to make the grub and other option visible again.