failed to install grub to /dev/sda

[Leandro Galliano]

I am trying to install Ubuntu Studio to my empty SSHD. The problem is that I don't understand very well how to prepare the partition table, initially, I use to do this, as MBR:

/dev/sda1 EFI 1024Mb
/dev/sda2 swap 2048Mb
/dev/sda3 / <remaining space>

Then I tried:

/dev/sda1 EFI 1024Mb
/dev/sda2 swap 2048Mb
/dev/sda3 /boot 2048Mb
/dev/sda4 / <remaining space>

And finally, restarted and clicked on the "Erase disk and install Ubuntu" option, but still getting the same error: "executing grub install /dev/sda failed".

I use to format the entire Solid Hard Drive with Parted Magic before installing a new system.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity 20.04.15.2
ProcVersionSignature: Ubuntu 5.4.0-42.46-lowlatency 5.4.44
Uname: Linux 5.4.0-42-lowlatency x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.4
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.445.1
Date: Sun Nov 15 19:26:42 2020
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntustudio.seed quiet splash ---
LiveMediaBuild: Ubuntu-Studio 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)