ual installation Windows to Ubuntu 21.04 not working

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There is no grub installed

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: ubiquity 21.04.19
ProcVersionSignature: Ubuntu 5.11.0-16.17-generic 5.11.12
Uname: Linux 5.11.0-16-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu65
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.461
CurrentDesktop: ubuntu:GNOME
Date: Mon May 24 22:28:10 2021
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 21.04 "Hirsute Hippo" - Release amd64 (20210420)
ProcEnviron:
 LANGUAGE=nl_NL.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=nl_NL.UTF-8
 LC_NUMERIC=C.UTF-8
RebootRequiredPkgs:
 linux-image-5.11.0-16-generic
 linux-base
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)