there where no errors - not in the output you shared here
(only from the two failed attempts to chroot into the wrong partition, 0 and 2)
…
It almost always pays to read a wiki or two and not fly blind.
As I quickly confirmed again when I did.
What you did here was just to update the bootloader configuration file.
That’s what update-grub does.
What you did not do was what you intended to do:
actually reinstall grub to the disk
I’d like to refer you to this: Manjaro wiki.
the EFI-System section about 3/4 into the page
after chroot
but before update-grub
you missed the one step that you initially wanted to do:
grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=manjaro --recheck
Thats what all that looks like, to me.