Grub won't install every time I try to install Backbox OS

[ghostriders]

These are the steps that I try:

First delete nvme0n1 data by filling the disk with zero's. This is done using AOMEI partition wizard on medicat USB.

Backbox OS USB won't boot unless I type in the boot menu 'nomodeset'.

I intend to install backbox OS (ubuntu 18.02 LTS) on 256 GB SDD, nvme0n1

The partitions are as followed:

50 mb reserved BIOS
512 mb EPS
500 mb /boot
16 GB for swap
and the rest of the SDD-space is intended for /

I always get the following error:

grub-efi-amd64-signed’ package failed to install into /target/

After rebooting I enter grub rescue

I have tried the following to fix this error:

I used the live USB and installed boot-repair on it.
Boot-repair does not function due to a lot of bugs

I installed Peppermint OS onto a USB and used boot-repair again.
However boot-repair did not function due to a lot of bugs

I have had Backbox OS working before, there were no issues with the installation

I hope you have a solution to this problem.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubiquity 18.04.14.12
ProcVersionSignature: Ubuntu 4.18.0-21.22~18.04.1-generic 4.18.20
Uname: Linux 4.18.0-21-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
CasperVersion: 1.394
Date: Sat Mar 14 13:55:24 2020
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/backbox.seed boot=casper only-ubiquity quiet splash nomodeset ---
LiveMediaBuild: BackBox Linux 6 - Release amd64 (20190610)
ProcEnviron:
 LANGUAGE=en_US.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 LC_NUMERIC=C.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)