Two more things you could try whilst in manjaro-chroot; reinstall your kernels and reinstall grub. To list your kernels:
mhwd-kernel li
and then to install them
pacman -S linuxXXX linuxYYY
To reinstall grub check here for all options, for your UEFI most likely:
grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=manjaro --recheck
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