Your boot partition has the correct flags but is calling a different bootloader and it fails. See line 46, it should be calling grubx64.efi (not shim) For Ubuntu, the pathname is \EFI\Ubuntu\grubx64.efi
(shimx64.efi is for secure boot).
Your boot partition has the correct flags but is calling a different bootloader and it fails. See line 46, it should be calling grubx64.efi (not shim) For Ubuntu, the pathname is \EFI\Ubuntu\grubx64.efi
(shimx64.efi is for secure boot).