Fresh installation of 21.10 from USB failed to install GRUB

After problems with an upgrade to 21.10 decided to do a fresh install of 21.10. After the installation completed a warning that GRUB could not be installed and request to file a bug report. The same thing occurred twice. First time doing REPAIR option, second when trying delete and reformat partition before installation

Separate HOME partition.

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: ubiquity 21.10.10
ProcVersionSignature: Ubuntu 5.13.0-19.19-generic 5.13.14
Uname: Linux 5.13.0-19-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu70
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.465
Date: Wed Nov 24 10:55:57 2021
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/xubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Xubuntu 21.10 "Impish Indri" - Release amd64 (20211012)
ProcEnviron:
 LANGUAGE=en_GB.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_GB.UTF-8
 LC_NUMERIC=C.UTF-8
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)