Ok. For me this can’t be solved. There you have the Manjaro entry in the list, but you say is not showing up in boot options and boot order is not afected. So I think there is nothing more we can do (at least me)
Installing for x86_64-efi platform.
Installation finished. No error reported.
Generating grub configuration file …
Found theme: /usr/share/grub/themes/manjaro/theme.txt
Found linux image: /boot/vmlinuz-5.8-x86_64
Found initrd image: /boot/intel-ucode.img /boot/initramfs-5.8-x86_64.img
Found initrd fallback image: /boot/initramfs-5.8-x86_64-fallback.img
Adding boot menu entry for UEFI Firmware Settings …
Found memtest86+ image: /boot/memtest86+/memtest.bin
/usr/bin/grub-probe: warning: unknown device type nvme0n1.
done
This is because of the memtest86 file in the grub actions and can be ignored or fixed by removing memtest86 file.
I didn’t read the all the messages as it started to be non sense to me, but I have Windows installed on UEFI/GPT on its own SSD, and I have Manjaro installed on its own NVME SSD as GPT/UEFI. My system boots on the NVME SSD, I have the grub boot menu entry where I can select to boot on Manjaro or Windows. I don’t know why your system doesn’t work but yeah you’re doing something wrong.
I suppose that was selected in the first installation of the wrong boot sector ?!
(probably the nvme was given and not the ssd (where Microsoft & co is on it)
not fail … next try
what amazes me, grub won’t find any other systems like Microsoft etc …
pls output from lsblk -al sudo ls -al /boot/efi/EFI/
(in the live usb & chroot or nvme install > no matter > where you are right now)
actually should now be:
/boot/efi → /dev/sda1 (MS, Co & NewManjaro)
/(root) → /dev/nvme0n1p3
assuming everything was done correctly?
What is the first Boot-Order in your BIOS/UEFI-Settings when booting?
**(i made a mistake. unfortunately read too much and lost sight of the goal.
wanted to help you too much (all systems under one GRUB)
and didn’t help with unkown device type: nvme0n1