They are identical in terms of content yes. The dates are different on my end too, just like in your case. You can confirm the content integrity by comparing the outputs of:
sudo md5sum /boot/efi/EFI/boot/bootx64.efi
sudo md5sum /boot/efi/EFI/Manjaro/grubx64.efi
For example on my end they’re both: 8ff4272e1bdb24fb82f6aeb51a9a239a, so their contents are identical, as they should be. You can also post the output of efibootmgr just to have some more intel.
Just to confirm, when you’re in Live USB mode, are you manjaro-chroot -ed into your actual system, before doing the grub-install, right?
@Dubliner - Since you’re on systemd, mkinitcpio got updated lately, there should be even a pacnew for it (DIFFPROG=meld pacdiff -s)
But anyways, try this in your /etc/mkinitcpio.conf:
From your current HOOKS=(base udev autodetect kms modconf block keyboard keymap consolefont plymouth encrypt openswap resume filesystems fsck)
Modify to new: HOOKS=(systemd autodetect kms modconf block keyboard sd-vconsole plymouth sd-encrypt openswap resume filesystems fsck)
Explanation: base has been replaced upstream with systemd, udev is optional for systemd, and both keymap and consolefont is also handled by sd-vconsole now because of systemd. Source. You can even leave out fsck aswell if you’re on btrfs, and pass is set to 0 on your rootfs within /etc/fstab.
Then sudo mkinitcpio -P and sudo update-grub. Reboot and cross fingers.